A randomised controlled trial of compression therapies for the treatment of venous leg ulcers (VenUS 6): study protocol for a pragmatic, multicentre, parallel-group, three-arm randomised controlled trial

BACKGROUND

Venous leg ulcer(s) are common, recurring, open wounds on the lower leg, resulting from diseased or damaged leg veins impairing blood flow. Wound healing is the primary treatment aim for venous leg ulceration, alongside the management of pain, wound exudate and infection. Full (high) compression therapy delivering 40 mmHg of pressure at the ankle is the recommended first-line treatment for venous leg ulcers. There are several different forms of compression therapy available including wraps, two-layer hosiery, and two-layer or four-layer bandages. There is good evidence for the clinical and cost-effectiveness of four-layer bandage and two-layer hosiery but more limited evidence for other treatments (two-layer bandage and compression wraps). Robust evidence is required to compare clinical and cost-effectiveness of these and to investigate which is the best compression treatment for reducing time to healing of venous leg ulcers whilst offering value for money. VenUS 6 will therefore investigate the clinical and cost-effectiveness of evidence-based compression, two-layer bandage and compression wraps for time to healing of venous leg ulcers.

METHODS

VenUS 6 is a pragmatic, multi-centre, three-arm, parallel-group, randomised controlled trial. Adult patients with a venous leg ulcer will be randomised to receive (1) compression wraps, (2) two-layer bandage or (3) evidence-based compression (two-layer hosiery or four-layer bandage). Participants will be followed up for between 4 and 12 months. The primary outcome will be time to healing (full epithelial cover in the absence of a scab) in days since randomisation. Secondary outcomes will include key clinical events (e.g. healing of the reference leg, ulcer recurrence, ulcer/skin deterioration, amputation, admission/discharge, surgery to close/remove incompetent superficial veins, infection or death), treatment changes, adherence and ease of use, ulcer related pain, health-related quality of life and resource use.

DISCUSSION

VenUS 6 will provide robust evidence on the clinical and cost-effectiveness of the different forms of compression therapies for venous leg ulceration. VenUS 6 opened to recruitment in January 2021 and is currently recruiting across 30 participating centres.

TRIAL REGISTRATION

ISRCTN67321719 . Prospectively registered on 14 September 2020.

Barriers and facilitators to use of compression therapy by people with venous leg ulcers: A qualitative exploration

AIMS

To explore barriers to, and facilitators of, adherence to compression therapy, from the perspective of people with venous leg ulcers.

DESIGN

An interpretive, qualitative, descriptive study involving interviews with patients.

METHODS

Participants were purposively sampled from respondents to a survey exploring attitudes to compression therapy in people with venous leg ulcers. Sampling continued until data saturation: 25 interviews between December 2019 and July 2020. Inductive thematic analysis of interview transcripts was undertaken to create a framework for the data, followed by deductive analysis informed by the Common-Sense Model of Self-Regulation.

RESULTS

A range of knowledge and understanding about the cause of venous leg ulcers and the mechanisms of compression therapy was demonstrated, which was not particularly related to adherence. Participants talked about their experience with different compression methods and their concerns about the length of time healing could take. They also spoke about aspects of the organization of services which affected their care.

CONCLUSION

Identifying specific, individual barriers/facilitators to compression therapy is not simple, rather factors combine to make adherence more or less likely or possible. There was no clear relationship between an understanding of the cause of VLUs or the mechanism of compression therapy and adherence; different compression therapies presented different challenges for patients; unintentional non-adherence was frequently mentioned; and the organization of services could impact on adherence. Ways in which people could be supported to adhere to compression therapy are indicated. Implications for practice include issues relating to communication with patients; taking into account patients' lifestyles and ensuring that they know about useful 'aids'; providing services that are accessible and provide continuity of appropriately trained staff; minimizing unintentional non-adherence; and acknowledging that healthcare professionals will always need to support/advise those who cannot tolerate compression.

IMPACT

Compression therapy is a cost-effective, evidence-based treatment for venous leg ulcers. However, there is evidence that patients do not always adhere to this therapy and there is limited research investigating reasons why patients do not wear compression. The study found no clear relationship between an understanding of the cause of VLUs or the mechanism of compression therapy and adherence; that different compression therapies presented different challenges for patients; that unintentional non-adherence was frequently mentioned and that the organization of services could impact on adherence. Attending to these findings offers the opportunity to increase the proportion of people undergoing appropriate compression therapy and achieving complete wound healing, the main outcome desired by this group.

PATIENT/PUBLIC CONTRIBUTION

A patient representative sits on the Study Steering Group, contributing to the work from developing the study protocol and interview schedule to interpretation and discussion of findings. Members of a Wounds Research Patient and Public Involvement Forum were consulted about interview questions.

The use and impact of digital COVID-19 tracking in adult social care: a prospective cohort study of care homes in Greater Manchester

BACKGROUND

To support proactive care during the coronavirus pandemic, a digital COVID-19 symptom tracker was deployed in Greater Manchester (UK) care homes. This study aimed to understand what factors were associated with the post-uptake use of the tracker and whether the tracker had any effects in controlling the spread of COVID-19.

METHODS

Daily data on COVID-19, tracker uptake and use, and other key indicators such as staffing levels, the number of staff self-isolating, availability of personal protective equipment, bed occupancy levels, and any problems in accepting new residents were analysed for 547 care homes across Greater Manchester for the period April 2020 to April 2021. Differences in tracker use across local authorities, types of care homes, and over time were assessed using correlated effects logistic regressions. Differences in numbers of COVID-19 cases in homes adopting versus not adopting the tracker were compared via event design difference-in-difference estimations.

RESULTS

Homes adopting the tracker used it on 44% of days post-adoption. Use decreased by 88% after one year of uptake (odds ratio 0.12; 95% confidence interval 0.06-0.28). Use was highest in the locality initiating the project (odds ratio 31.73; 95% CI 3.76-268.05). Care homes owned by a chain had lower use (odds ratio 0.30; 95% CI 0.14-0.63 versus single ownership care homes), and use was not associated with COVID-19 or staffing levels. Tracker uptake had no impact on controlling COVID-19 spread. Staff self-isolating and local area COVID-19 cases were positively associated with lagged COVID-19 spread in care homes (relative risks 1.29; 1.2-1.4 and 1.05; 1.0-1.1, respectively).

CONCLUSIONS

The use of the COVID-19 symptom tracker in care homes was not maintained except in Locality 1 and did not appear to reduce the COVID-19 spread. COVID-19 cases in care homes were mainly driven by care home local-area COVID-19 cases and infections among the staff members. Digital deterioration trackers should be co-produced with care home staff, and local authorities should provide long-term support in their adoption and use.

Implementation, uptake and use of a digital COVID-19 symptom tracker in English care homes in the coronavirus pandemic: a mixed-methods, multi-locality case study

BACKGROUND

COVID-19 spread rapidly in UK care homes for older people in the early pandemic. National infection control recommendations included remote resident assessment. A region in North-West England introduced a digital COVID-19 symptom tracker for homes to identify early signs of resident deterioration to facilitate care responses. We examined the implementation, uptake and use of the tracker in care homes across four geographical case study localities in the first year of the pandemic.

METHODS

This was a rapid, mixed-methods, multi-locality case study. Tracker uptake was calculated using the number of care homes taking up the tracker as a proportion of the total number of care homes in a locality. Mean tracker use was summarised at locality level and compared. Semi-structured interviews were conducted with professionals involved in tracker implementation and used to explore implementation factors across localities. Template Analysis with the Consolidated Framework for Implementation Research (CFIR) guided the interpretation of qualitative data.

RESULTS

Uptake varied across the four case study localities ranging between 13.8 and 77.8%. Tracker use decreased in all localities over time at different rates, with average use ranging between 18 and 58%. The implementation context differed between localities and the process of implementation deviated over time from the initially planned strategy, for stakeholder engagement and care homes' training. Four interpretative themes reflected the most influential factors appearing to affect tracker uptake and use: (1) the process of implementation, (2) implementation readiness, (3) clarity of purpose/perceived value and (4) relative priority in the context of wider system pressures.

CONCLUSIONS

Our study findings resonate with the digital solutions evidence base prior to the COVID-19 pandemic, suggesting three key factors that can inform future development and implementation of rapid digital responses in care home settings even in times of crisis: an incremental approach to implementation with testing of organisational readiness and attention to implementation climate, particularly the innovation's fit with local contexts (i.e. systems, infrastructure, work processes and practices); involvement of end-users in innovation design and development; and enabling users' easy access to sustained, high-quality, appropriate training and support to enable staff to adapt to digital solutions.

Introducing the '3 Fs model of complexity' for people with dementia accessing a NHS mental health inpatient dementia assessment ward: An interpretive description study

BACKGROUND

In the United Kingdom, the use of the terms 'complex' and 'complexity' alongside dementia is reflected in a number of policy and practice documents. However, there is a lack of evidence that explores how complexity is perceived, constructed and experienced by people with dementia, family carers and practitioners working in the NHS dementia inpatient assessment wards [dementia assessment wards].

OBJECTIVE

To explore the meaning and concept of complexity in dementia from within the setting of a dementia assessment ward and develop a practice model.

METHODS

The study was conducted over three phases: 1) an online electronic survey of UK national dementia leaders; 2) individual interviews and a focus group with dementia practitioners in two dementia assessment wards; 3) case studies of four patients with dementia resident on a dementia assessment ward which included their identified family carer/consultee, the named clinician on the ward involved in that person's care and a care records review.

RESULTS

The findings highlighted that complexity is constructed through a number of interconnected and interrelated domains that vary in acuity. These findings have been developed into the '3 Fs Model of Complexity' and the 3'Fs' stand for Fixed, Flexible and Fluctuating. The Fixed domain consists of six components which are always present in complexity. The Flexible domain consists of 14 components and a person with dementia may experience any number of Flexible domain components at any one time. The Fluctuating domain highlights that all components have the ability to vary in their acuity.

CONCLUSION

The '3 Fs Model of Complexity' may facilitate a more holistic view of a person with dementia than when 'symptoms' are viewed in isolation. Going forward, and subject to further refinement and testing, the '3 Fs Model of Complexity' could help guide the selection of tailored, personalised interventions for people with dementia, including formulation approaches.

“Negotiating a new normality” - a longitudinal qualitative exploration of the meaning of living with an open surgical wound

Purpose

Little is known about the experiences of people living with open surgical wounds. These wounds are common and predominantly affect young and actively working people. The aim of this qualitative study was to explore the meaning of living with open surgical wounds.

Methods

A qualitative exploratory study was conducted. We collected data using two individual interviews with each of ten participants (aged between 18–73 years) who had open surgical wounds. Our analytical approach was based on qualitative content analysis. Methods are reported using COREQ guidelines.

Results

We found that the meaning of living with open surgical wounds is shaped by five subthemes: “enduring healing”, “life disruption”, “adapting to a new reality”, “striving for healing” and “returning to normal life;” all under an overarching theme of “negotiating a new normality”.

Conclusion

Participants’ well-being and everyday living are greatly impacted by open surgical wounds. Findings from this study emphasize that open surgical wounds are a long-term condition with a typical “chronicity” trajectory; this brings a new perspective to previous findings of studies on living with complex wounds. This study has also highlighted areas for further research, related to improving individuals’ experience of living with open surgical wounds.

Approaches to enabling rapid evaluation of innovations in health and social care: a scoping review of evidence from high-income countries

OBJECTIVE

The COVID-19 pandemic increased the demand for rapid evaluation of innovation in health and social care. Assessment of rapid methodologies is lacking although challenges in ensuring rigour and effective use of resources are known. We mapped reports of rapid evaluations of health and social care innovations, categorised different approaches to rapid evaluation, explored comparative benefits of rapid evaluation, and identified knowledge gaps.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, EMBASE and Health Management Information Consortium (HMIC) databases were searched through 13 September 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included publications reporting primary research or methods for rapid evaluation of interventions or services in health and social care in high-income countries.

DATA EXTRACTION AND SYNTHESIS

Two reviewers developed and piloted a data extraction form. One reviewer extracted data, a second reviewer checked 10% of the studies; disagreements and uncertainty were resolved through consensus. We used narrative synthesis to map different approaches to conducting rapid evaluation.

RESULTS

We identified 16 759 records and included 162 which met inclusion criteria.We identified four main approaches for rapid evaluation: (1) Using methodology designed specifically for rapid evaluation; (2) Increasing rapidity by doing less or using less time-intensive methodology; (3) Using alternative technologies and/or data to increase speed of existing evaluation method; (4) Adapting part of non-rapid evaluation.The COVID-19 pandemic resulted in an increase in publications and some limited changes in identified methods. We found little research comparing rapid and non-rapid evaluation.

CONCLUSIONS

We found a lack of clarity about what 'rapid evaluation' means but identified some useful preliminary categories. There is a need for clarity and consistency about what constitutes rapid evaluation; consistent terminology in reporting evaluations as rapid; development of specific methodologies for making evaluation more rapid; and assessment of advantages and disadvantages of rapid methodology in terms of rigour, cost and impact.

Rapid evidence synthesis to enable innovation and adoption in health and social care

BACKGROUND

The rapid identification and adoption of effective innovations in healthcare is a known challenge. The strongest evidence base for innovations can be provided by evidence synthesis, but this is frequently a lengthy process and even rapid versions of this can be time-consuming and complex. In the UK, the Accelerated Access Review and Academic Health Science Network (AHSN) have provided the impetus to develop a consistently rapid process to support the identification and adoption of high-value innovations in the English NHS.

METHODS

The Greater Manchester Applied Research Collaboration (ARC-GM) developed a framework for a rapid evidence synthesis (RES) approach, which is highly integrated within the innovation process of the Greater Manchester AHSN and the associated healthcare and research ecosystem. The RES uses evidence synthesis approaches and draws on the GRADE Evidence to Decision framework to provide rapid assessments of the existing evidence and its relevance to specific decision problems. We implemented this in a real-time context of decision-making around adoption of innovative health technologies.

RESULTS

Key stakeholders in the Greater Manchester decision-making process for healthcare innovations have found that our approach is both timely and flexible; it is valued for its combination of rigour and speed. Our RES approach rapidly and systematically identifies, appraises and contextualises relevant evidence, which can then be transparently incorporated into decisions about the wider adoption of innovations. The RES also identifies limitations in existing evidence for innovations and this can inform subsequent evaluations. There is substantial interest from other ARCs and AHSNs in implementing a similar process. We are currently exploring methods to make completed RES publicly available. We are also exploring methods to evaluate the impact of using RES as more implementation decisions are made.

CONCLUSIONS

The RES framework we have implemented combines transparency and consistency with flexibility and rapidity. It therefore maximises utility in a real-time decision-making context for healthcare innovations.

The accuracy of pulse oximetry in measuring oxygen saturation by levels of skin pigmentation: a systematic review and meta-analysis

BACKGROUND

During the COVID-19 pandemic, there have been concerns regarding potential bias in pulse oximetry measurements for people with high levels of skin pigmentation. We systematically reviewed the effects of skin pigmentation on the accuracy of oxygen saturation measurement by pulse oximetry (SpO2) compared with the gold standard SaO2 measured by CO-oximetry.

METHODS

We searched Ovid MEDLINE, Ovid Embase, EBSCO CINAHL, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform (up to December 2021) for studies with SpO2-SaO2 comparisons and measuring the impact of skin pigmentation or ethnicity on pulse oximetry accuracy. We performed meta-analyses for mean bias (the primary outcome in this review) and its standard deviations (SDs) across studies included for each subgroup of skin pigmentation and ethnicity and used these pooled mean biases and SDs to calculate accuracy root-mean-square (Arms) and 95% limits of agreement. The review was registered with the Open Science Framework ( https://osf.io/gm7ty ).

RESULTS

We included 32 studies (6505 participants): 15 measured skin pigmentation and 22 referred to ethnicity. Compared with standard SaO2 measurement, pulse oximetry probably overestimates oxygen saturation in people with the high level of skin pigmentation (pooled mean bias 1.11%; 95% confidence interval 0.29 to 1.93%) and people described as Black/African American (1.52%; 0.95 to 2.09%) (moderate- and low-certainty evidence). The bias of pulse oximetry measurements for people with other levels of skin pigmentation or those from other ethnic groups is either more uncertain or suggests no overestimation. Whilst the extent of mean bias is small or negligible for all subgroups evaluated, the associated imprecision is unacceptably large (pooled SDs > 1%). When the extent of measurement bias and precision is considered jointly, pulse oximetry measurements for all the subgroups appear acceptably accurate (with Arms < 4%).

CONCLUSIONS

Pulse oximetry may overestimate oxygen saturation in people with high levels of skin pigmentation and people whose ethnicity is reported as Black/African American, compared with SaO2. The extent of overestimation may be small in hospital settings but unknown in community settings. REVIEW PROTOCOL REGISTRATION: https://osf.io/gm7ty.

What promotes or prevents greater use of appropriate compression in people with venous leg ulcers? A qualitative interview study with nurses in the north of England using the Theoretical Domains Framework

OBJECTIVES

To investigate factors that promote and prevent the use of compression therapy in people with venous leg ulcers.

DESIGN

Qualitative interview study with nurses using the Theoretical Domains Framework (TDF).

SETTING

Three National Health Service Trusts in England.

PARTICIPANTS

Purposive sample of 15 nurses delivering wound care.

RESULTS

Nurses described factors which made provision of compression therapy challenging. Organisational barriers (TDF domains environmental context and resources/knowledge, skills/behavioural regulation) included heavy/increasing caseloads; lack of knowledge/skills and the provision of training; and prescribing issues (variations in bandaging systems/whether nurses could prescribe). Absence of specialist leg ulcer services to refer patients into was perceived as a barrier to providing optimal care by some community-based nurses. Compression use was perceived to be facilitated by clinics for timely initial assessment; continuity of staff and good liaison between vascular/leg ulcer clinics and community teams; clear local policies and care pathways; and opportunities for training such as 'shadowing' in vascular/leg ulcer clinics. Patient engagement barriers (TDF domains goals/beliefs about consequences) focused on getting patients 'on board' with compression, and supporting them in using it. Clear explanations were seen as key in promoting compression use.

CONCLUSIONS

Rising workload pressures present significant challenges to enhancing leg ulcer services. There may be opportunities to develop facilitated approaches to enable community nursing teams to make changes to practice, enhancing quality of patient care. The majority of venous leg ulcers could be managed in the community without referral to specialist community services if issues relating to workloads/skills/training are addressed. Barriers to promoting compression use could also be targeted, for example, through the development of clear patient information leaflets. While the patient engagement barriers may be easier/quicker to address than organisational barriers, unless organisational barriers are addressed it seems unlikely that all people who would benefit from compression therapy will receive it.

Wound fluid sampling methods for proteomic studies: A scoping review

Understanding why some wounds are hard to heal is important for improving care and developing more effective treatments. The method of sample collection used is an integral step in the research process and thus may affect the results obtained. The primary objective of this study was to summarise and map the methods currently used to sample wound fluid for protein profiling and analysis. Eligible studies were those that used a sampling method to collect wound fluid from any human wound for analysis of proteins. A search for eligible studies was performed using MEDLINE, Embase and CINAHL Plus in May 2020. All references were screened for eligibility by one reviewer, followed by discussion and consensus with a second reviewer. Quantitative data were mapped and visualised using appropriate software and summarised via a narrative summary. After screening, 280 studies were included in this review. The most commonly used group of wound fluid collection methods were vacuum, drainage or use of other external devices, with surgical wounds being the most common sample source. Other frequently used collection methods were extraction from absorbent materials, collection beneath an occlusive dressing and direct collection of wound fluid. This scoping review highlights the variety of methods used for wound fluid collection. Many studies had small sample sizes and short sample collection periods; these weaknesses have hampered the discovery and validation of novel biomarkers. Future research should aim to assess the reproducibility and feasibility of sampling and analytical methods for use in larger longitudinal studies.

Health service costs of treating venous leg ulcers in the UK: evidence from a cross-sectional survey based in the north west of England

OBJECTIVES

To estimate and examine the direct healthcare costs of treating people with open venous leg ulcers in the UK.

DESIGN

Cost-of-illness study.

SETTING

A cross-sectional survey of nine National Health Service community locales over 2-week periods in 2015/2016.

METHODS

We examined the resource use and prevalence of venous leg ulcer treatment in the community. Examination of variation in these obtained costs was performed by ordinary least squares regression. We used additional resource use information from a randomised control trial and extrapolated costs to the UK for an annual period.

RESULTS

The average 2-week per person cost of treating patients where a venous leg ulceration was the primary (most severe) wound was estimated at £166.39 (95% CI £157.78 to £175.00) with community staff time making up over half of this amount. Costs were higher where antimicrobial dressings were used and where wound care was delivered in the home. Among those with any recorded venous leg ulcer (primary and non-primary), we derived a point prevalence of 3.2 per 10 000 population and estimated that the annual prevalence could be no greater than 82.4 per 10 000 population. We estimated that the national cost of treating a venous leg ulcer was £102 million with a per person annual cost at £4787.70.

CONCLUSION

Our point prevalence figures are in line with the literature. However, our annual prevalence estimations and costs are far lower than those reported in recent literature which suggests that the costs of treating venous leg ulcers are lower than previously thought. Movement towards routinely collected and useable community care activity would help provide a transparent and deeper understanding of the scale and cost of wound care in the UK.

Beds, overlays and mattresses for preventing and treating pressure ulcers: an overview of Cochrane Reviews and network meta-analysis

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Specific kinds of beds, overlays and mattresses are widely used with the aim of preventing and treating pressure ulcers.

OBJECTIVES

To summarise evidence from Cochrane Reviews that assess the effects of beds, overlays and mattresses on reducing the incidence of pressure ulcers and on increasing pressure ulcer healing in any setting and population. To assess the relative effects of different types of beds, overlays and mattresses for reducing the incidence of pressure ulcers and increasing pressure ulcer healing in any setting and population. To cumulatively rank the different treatment options of beds, overlays and mattresses in order of their effectiveness in pressure ulcer prevention and treatment.

METHODS

In July 2020, we searched the Cochrane Library. Cochrane Reviews reporting the effectiveness of beds, mattresses or overlays for preventing or treating pressure ulcers were eligible for inclusion in this overview. Two review authors independently screened search results and undertook data extraction and risk of bias assessment using the ROBIS tool. We summarised the reported evidence in an overview of reviews. Where possible, we included the randomised controlled trials from each included review in network meta-analyses. We assessed the relative effectiveness of beds, overlays and mattresses for preventing or treating pressure ulcers and their probabilities of being, comparably, the most effective treatment. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We include six Cochrane Reviews in this overview of reviews, all at low or unclear risk of bias. Pressure ulcer prevention: four reviews (of 68 studies with 18,174 participants) report direct evidence for 27 pairwise comparisons between 12 types of support surface on the following outcomes: pressure ulcer incidence, time to pressure ulcer incidence, patient comfort response, adverse event rates, health-related quality of life, and cost-effectiveness. Here we focus on outcomes with some evidence at a minimum of low certainty. (1) Pressure ulcer incidence: our overview includes direct evidence for 27 comparisons that mostly (19/27) have very low-certainty evidence concerning reduction of pressure ulcer risk. We included 40 studies (12,517 participants; 1298 participants with new ulcers) in a network meta-analysis involving 13 types of intervention. Data informing the network are sparse and this, together with the high risk of bias in most studies informing the network, means most network contrasts (64/78) yield evidence of very low certainty. There is low-certainty evidence that, compared with foam surfaces (reference treatment), reactive air surfaces (e.g. static air overlays) (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.29 to 0.75), alternating pressure (active) air surfaces (e.g. alternating pressure air mattresses, large-celled ripple mattresses) (RR 0.63, 95% CI 0.42 to 0.93), and reactive gel surfaces (e.g. gel pads used on operating tables) (RR 0.47, 95% CI 0.22 to 1.01) may reduce pressure ulcer incidence. The ranking of treatments in terms of effectiveness is also of very low certainty for all interventions. It is unclear which treatment is best for preventing ulceration. (2) Time to pressure ulcer incidence: four reviews had direct evidence on this outcome for seven comparisons. We included 10 studies (7211 participants; 699 participants with new ulcers) evaluating six interventions in a network meta-analysis. Again, data from most network contrasts (13/15) are of very low certainty. There is low-certainty evidence that, compared with foam surfaces (reference treatment), reactive air surfaces may reduce the hazard of developing new pressure ulcers (hazard ratio (HR) 0.20, 95% CI 0.04 to 1.05). The ranking of all support surfaces for preventing pressure ulcers in terms of time to healing is uncertain. (3) Cost-effectiveness: this overview includes direct evidence for three comparisons. For preventing pressure ulcers, alternating pressure air surfaces are probably more cost-effective than foam surfaces (moderate-certainty evidence). Pressure ulcer treatment: two reviews (of 12 studies with 972 participants) report direct evidence for five comparisons on: complete pressure ulcer healing, time to complete pressure ulcer healing, patient comfort response, adverse event rates, and cost-effectiveness. Here we focus on outcomes with some evidence at a minimum of low certainty. (1) Complete pressure ulcer healing: our overview includes direct evidence for five comparisons. There is uncertainty about the relative effects of beds, overlays and mattresses on ulcer healing. The corresponding network meta-analysis (with four studies, 397 participants) had only three direct contrasts and a total of six network contrasts. Again, most network contrasts (5/6) have very low-certainty evidence. There was low-certainty evidence that more people with pressure ulcers may heal completely using reactive air surfaces than using foam surfaces (RR 1.32, 95% CI 0.96 to 1.80). We are uncertain which surfaces have the highest probability of being the most effective (all very low-certainty evidence). (2) Time to complete pressure ulcer healing: this overview includes direct evidence for one comparison: people using reactive air surfaces may be more likely to have healed pressure ulcers compared with those using foam surfaces in long-term care settings (HR 2.66, 95% CI 1.34 to 5.17; low-certainty evidence). (3) Cost-effectiveness: this overview includes direct evidence for one comparison: compared with foam surfaces, reactive air surfaces may cost an extra 26 US dollars for every ulcer-free day in the first year of use in long-term care settings (low-certainty evidence).

AUTHORS' CONCLUSIONS

Compared with foam surfaces, reactive air surfaces may reduce pressure ulcer risk and may increase complete ulcer healing. Compared with foam surfaces, alternating pressure air surfaces may reduce pressure ulcer risk and are probably more cost-effective in preventing pressure ulcers. Compared with foam surfaces, reactive gel surfaces may reduce pressure ulcer risk, particularly for people in operating rooms and long-term care settings. There are uncertainties for the relative effectiveness of other support surfaces for preventing and treating pressure ulcers, and their efficacy ranking. More high-quality research is required; for example, for the comparison of reactive air surfaces with alternating pressure air surfaces. Future studies should consider time-to-event outcomes and be designed to minimise any risk of bias.

Compression bandages or stockings versus no compression for treating venous leg ulcers

BACKGROUND

Leg ulcers are open skin wounds on the lower leg that can last weeks, months or even years. Most leg ulcers are the result of venous diseases. First-line treatment options often include the use of compression bandages or stockings.

OBJECTIVES

To assess the effects of using compression bandages or stockings, compared with no compression, on the healing of venous leg ulcers in any setting and population.

SEARCH METHODS

In June 2020 we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions by language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that compared any types of compression bandages or stockings with no compression in participants with venous leg ulcers in any setting.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, and risk-of-bias assessment using the Cochrane risk-of-bias tool. We assessed the certainty of the evidence according to GRADE methodology.

MAIN RESULTS

We included 14 studies (1391 participants) in the review. Most studies were small (median study sample size: 51 participants). Participants were recruited from acute-care settings, outpatient settings and community settings, and a large proportion (65.9%; 917/1391) of participants had a confirmed history or clinical evidence of chronic venous disease, a confirmed cause of chronic venous insufficiency, or an ankle pressure/brachial pressure ratio of greater than 0.8 or 0.9. The average age of participants ranged from 58.0 to 76.5 years (median: 70.1 years). The average duration of their leg ulcers ranged from 9.0 weeks to 31.6 months (median: 22.0 months), and a large proportion of participants (64.8%; 901/1391) had ulcers with an area between 5 and 20 cm². Studies had a median follow-up of 12 weeks. Compression bandages or stockings applied included short-stretch bandage, four-layer compression bandage, and Unna's boot (a type of inelastic gauze bandage impregnated with zinc oxide), and comparator groups used included 'usual care', pharmacological treatment, a variety of dressings, and a variety of treatments where some participants received compression (but it was not the norm). Of the 14 included studies, 10 (71.4%) presented findings which we consider to be at high overall risk of bias. Primary outcomes There is moderate-certainty evidence (downgraded once for risk of bias) (1) that there is probably a shorter time to complete healing of venous leg ulcers in people wearing compression bandages or stockings compared with those not wearing compression (pooled hazard ratio for time-to-complete healing 2.17, 95% confidence interval (CI) 1.52 to 3.10; I² = 59%; 5 studies, 733 participants); and (2) that people treated using compression bandages or stockings are more likely to experience complete ulcer healing within 12 months compared with people with no compression (10 studies, 1215 participants): risk ratio for complete healing 1.77, 95% CI 1.41 to 2.21; I² = 65% (8 studies with analysable data, 1120 participants); synthesis without meta-analysis suggests more completely-healed ulcers in compression bandages or stockings than in no compression (2 studies without analysable data, 95 participants). It is uncertain whether there is any difference in rates of adverse events between using compression bandages or stockings and no compression (very low-certainty evidence; 3 studies, 585 participants). Secondary outcomes Moderate-certainty evidence suggests that people using compression bandages or stockings probably have a lower mean pain score than those not using compression (four studies with 859 participants and another study with 69 ulcers): pooled mean difference -1.39, 95% CI -1.79 to -0.98; I² = 65% (two studies with 426 participants and another study with 69 ulcers having analysable data); synthesis without meta-analysis suggests a reduction in leg ulcer pain in compression bandages or stockings, compared with no compression (two studies without analysable data, 433 participants). Compression bandages or stockings versus no compression may improve disease-specific quality of life, but not all aspects of general health status during the follow-up of 12 weeks to 12 months (four studies with 859 participants; low-certainty evidence). It is uncertain if the use of compression bandages or stockings is more cost-effective than not using them (three studies with 486 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

If using compression bandages or stockings, people with venous leg ulcers probably experience complete wound healing more quickly, and more people have wounds completely healed. The use of compression bandages or stockings probably reduces pain and may improve disease-specific quality of life. There is uncertainty about adverse effects, and cost effectiveness. Future research should focus on comparing alternative bandages and stockings with the primary endpoint of time to complete wound healing alongside adverse events including pain score, and health-related quality of life, and should incorporate cost-effectiveness analysis where possible. Future studies should adhere to international standards of trial conduct and reporting.

Long-term Clinical and Cost-effectiveness of Early Endovenous Ablation in Venous Ulceration: A Randomized Clinical Trial

Importance

One-year outcomes from the Early Venous Reflux Ablation (EVRA) randomized trial showed accelerated venous leg ulcer healing and greater ulcer-free time for participants who are treated with early endovenous ablation of lower extremity superficial reflux.

Objective

To evaluate the clinical and cost-effectiveness of early endovenous ablation of superficial venous reflux in patients with venous leg ulceration.

Design, Setting, and Participants

Between October 24, 2013, and September 27, 2016, the EVRA randomized clinical trial enrolled 450 participants (450 legs) with venous leg ulceration of less than 6 months' duration and superficial venous reflux. Initially, 6555 patients were assessed for eligibility, and 6105 were excluded for reasons including ulcer duration greater than 6 months, healed ulcer by the time of randomization, deep venous occlusive disease, and insufficient superficial venous reflux to warrant ablation therapy, among others. A total of 426 of 450 participants (94.7%) from the vascular surgery departments of 20 hospitals in the United Kingdom were included in the analysis for ulcer recurrence. Surgeons, participants, and follow-up assessors were not blinded to the treatment group. Data were analyzed from August 11 to November 4, 2019.

Interventions

Patients were randomly assigned to receive compression therapy with early endovenous ablation within 2 weeks of randomization (early intervention, n = 224) or compression with deferred endovenous treatment of superficial venous reflux (deferred intervention, n = 226). Endovenous modality and strategy were left to the preference of the treating clinical team.

Main Outcomes and Measures

The primary outcome for the extended phase was time to first ulcer recurrence. Secondary outcomes included ulcer recurrence rate and cost-effectiveness.

Results

The early-intervention group consisted of 224 participants (mean [SD] age, 67.0 [15.5] years; 127 men [56.7%]; 206 White participants [92%]). The deferred-intervention group consisted of 226 participants (mean [SD] age, 68.9 [14.0] years; 120 men [53.1%]; 208 White participants [92%]). Of the 426 participants whose leg ulcer had healed, 121 (28.4%) experienced at least 1 recurrence during follow-up. There was no clear difference in time to first ulcer recurrence between the 2 groups (hazard ratio, 0.82; 95% CI, 0.57-1.17; P = .28). Ulcers recurred at a lower rate of 0.11 per person-year in the early-intervention group compared with 0.16 per person-year in the deferred-intervention group (incidence rate ratio, 0.658; 95% CI, 0.480-0.898; P = .003). Time to ulcer healing was shorter in the early-intervention group for primary ulcers (hazard ratio, 1.36; 95% CI, 1.12-1.64; P = .002). At 3 years, early intervention was 91.6% likely to be cost-effective at a willingness to pay of £20 000 ($26 283) per quality-adjusted life year and 90.8% likely at a threshold of £35 000 ($45 995) per quality-adjusted life year.

Conclusions and Relevance

Early endovenous ablation of superficial venous reflux was highly likely to be cost-effective over a 3-year horizon compared with deferred intervention. Early intervention accelerated the healing of venous leg ulcers and reduced the overall incidence of ulcer recurrence.

Trial Registration

ClinicalTrials.gov identifier: ISRCTN02335796.

Alternating pressure (active) air surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Alternating pressure (active) air surfaces are widely used with the aim of preventing pressure ulcers.

OBJECTIVES

To assess the effects of alternating pressure (active) air surfaces (beds, mattresses or overlays) compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to alternating pressure (active) air beds, overlays or mattresses. Comparators were any beds, overlays or mattresses.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

We included 32 studies (9058 participants) in the review. Most studies were small (median study sample size: 83 participants). The average age of participants ranged from 37.2 to 87.0 years (median: 69.1 years). Participants were largely from acute care settings (including accident and emergency departments). We synthesised data for six comparisons in the review: alternating pressure (active) air surfaces versus: foam surfaces, reactive air surfaces, reactive water surfaces, reactive fibre surfaces, reactive gel surfaces used in the operating room followed by foam surfaces used on the ward bed, and another type of alternating pressure air surface. Of the 32 included studies, 25 (78.1%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

pressure ulcer incidence Alternating pressure (active) air surfaces may reduce the proportion of participants developing a new pressure ulcer compared with foam surfaces (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.34 to 1.17; I² = 63%; 4 studies, 2247 participants; low-certainty evidence). Alternating pressure (active) air surfaces applied on both operating tables and hospital beds may reduce the proportion of people developing a new pressure ulcer compared with reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds (RR 0.22, 95% CI 0.06 to 0.76; I² = 0%; 2 studies, 415 participants; low-certainty evidence). It is uncertain whether there is a difference in the proportion of people developing new pressure ulcers between alternating pressure (active) air surfaces and the following surfaces, as all these comparisons have very low-certainty evidence: (1) reactive water surfaces; (2) reactive fibre surfaces; and (3) reactive air surfaces. The comparisons between different types of alternating pressure air surfaces are presented narratively. Overall, all comparisons suggest little to no difference between these surfaces in pressure ulcer incidence (7 studies, 2833 participants; low-certainty evidence). Included studies have data on time to pressure ulcer incidence for three comparisons. When time to pressure ulcer development is considered using a hazard ratio (HR), it is uncertain whether there is a difference in the risk of developing new pressure ulcers, over 90 days' follow-up, between alternating pressure (active) air surfaces and foam surfaces (HR 0.41, 95% CI 0.10 to 1.64; I² = 86%; 2 studies, 2105 participants; very low-certainty evidence). For the comparison with reactive air surfaces, there is low-certainty evidence that people treated with alternating pressure (active) air surfaces may have a higher risk of developing an incident pressure ulcer than those treated with reactive air surfaces over 14 days' follow-up (HR 2.25, 95% CI 1.05 to 4.83; 1 study, 308 participants). Neither of the two studies with time to ulcer incidence data suggested a difference in the risk of developing an incident pressure ulcer over 60 days' follow-up between different types of alternating pressure air surfaces. Secondary outcomes The included studies have data on (1) support-surface-associated patient comfort for comparisons involving foam surfaces, reactive air surfaces, reactive fibre surfaces and alternating pressure (active) air surfaces; (2) adverse events for comparisons involving foam surfaces, reactive gel surfaces and alternating pressure (active) air surfaces; and (3) health-related quality of life outcomes for the comparison involving foam surfaces. However, all these outcomes and comparisons have low or very low-certainty evidence and it is uncertain whether there are any differences in these outcomes. Included studies have data on cost effectiveness for two comparisons. Moderate-certainty evidence suggests that alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces (1 study, 2029 participants) and that alternating pressure (active) air mattresses are probably more cost-effective than overlay versions of this technology for people in acute care settings (1 study, 1971 participants).

AUTHORS' CONCLUSIONS

Current evidence is uncertain about the difference in pressure ulcer incidence between using alternating pressure (active) air surfaces and other surfaces (reactive water surfaces, reactive fibre surfaces and reactive air surfaces). Alternating pressure (active) air surfaces may reduce pressure ulcer risk compared with foam surfaces and reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds. People using alternating pressure (active) air surfaces may be more likely to develop new pressure ulcers over 14 days' follow-up than those treated with reactive air surfaces in the nursing home setting; but as the result is sensitive to the choice of outcome measure it should be interpreted cautiously. Alternating pressure (active) air surfaces are probably more cost-effective than reactive foam surfaces in preventing new pressure ulcers. Future studies should include time-to-event outcomes and assessment of adverse events and trial-level cost-effectiveness. Further review using network meta-analysis will add to the findings reported here.

Beds, overlays and mattresses for treating pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Beds, overlays or mattresses are widely used with the aim of treating pressure ulcers.

OBJECTIVES

To assess the effects of beds, overlays and mattresses on pressure ulcer healing in people with pressure ulcers of any stage, in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to pressure-redistributing beds, overlays or mattresses. Comparators were any beds, overlays or mattresses that were applied for treating pressure ulcers.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

We included 13 studies (972 participants) in the review. Most studies were small (median study sample size: 72 participants). The average age of participants ranged from 64.0 to 86.5 years (median: 82.7 years) and all studies recruited people with existing pressure ulcers (the baseline ulcer area size ranging from 4.2 to 18.6 cm²,median 6.6 cm²). Participants were recruited from acute care settings (six studies) and community and long-term care settings (seven studies). Of the 13 studies, three (224 participants) involved surfaces that were not well described and therefore could not be classified. Additionally, six (46.2%) of the 13 studies presented findings which were considered at high overall risk of bias. We synthesised data for four comparisons in the review: alternating pressure (active) air surfaces versus foam surfaces; reactive air surfaces versus foam surfaces; reactive water surfaces versus foam surfaces, and a comparison between two types of alternating pressure (active) air surfaces. We summarise key findings for these four comparisons below. (1) Alternating pressure (active) air surfaces versus foam surfaces: we are uncertain if there is a difference between alternating pressure (active) air surfaces and foam surfaces in the proportion of participants whose pressure ulcers completely healed (two studies with 132 participants; the reported risk ratio (RR) in one study was 0.97, 95% confidence interval (CI) 0.26 to 3.58). There is also uncertainty for the outcomes of patient comfort (one study with 83 participants) and adverse events (one study with 49 participants). These outcomes have very low-certainty evidence. Included studies did not report time to complete ulcer healing, health-related quality of life, or cost effectiveness. (2) Reactive air surfaces versus foam surfaces: it is uncertain if there is a difference in the proportion of participants with completely healed pressure ulcers between reactive air surfaces and foam surfaces (RR 1.32, 95% CI 0.96 to 1.80; I² = 0%; 2 studies, 156 participants; low-certainty evidence). When time to complete pressure ulcer healing is considered using a hazard ratio, data from one small study (84 participants) suggests a greater hazard for complete ulcer healing on reactive air surfaces (hazard ratio 2.66, 95% CI 1.34 to 5.17; low-certainty evidence). These results are sensitive to the choice of outcome measure so should be interpreted as uncertain. We are also uncertain whether there is any difference between these surfaces in patient comfort responses (1 study, 72 participants; very low-certainty evidence) and in adverse events (2 studies, 156 participants; low-certainty evidence). There is low-certainty evidence that reactive air surfaces may cost an extra 26 US dollars for every ulcer-free day in the first year of use (1 study, 87 participants). Included studies did not report health-related quality of life. (3) Reactive water surfaces versus foam surfaces: it is uncertain if there is a difference between reactive water surfaces and foam surfaces in the proportion of participants with healed pressure ulcers (RR 1.07, 95% CI 0.70 to 1.63; 1 study, 101 participants) and in adverse events (1 study, 120 participants). All these have very low-certainty evidence. Included studies did not report time to complete ulcer healing, patient comfort, health-related quality of life, or cost effectiveness. (4) Comparison between two types of alternating pressure (active) air surfaces: it is uncertain if there is a difference between Nimbus and Pegasus alternating pressure (active) air surfaces in the proportion of participants with healed pressure ulcers, in patient comfort responses and in adverse events: each of these outcomes had four studies (256 participants) but very low-certainty evidence. Included studies did not report time to complete ulcer healing, health-related quality of life, or cost effectiveness.

AUTHORS' CONCLUSIONS

We are uncertain about the relative effects of most different pressure-redistributing surfaces for pressure ulcer healing (types directly compared are alternating pressure air surfaces versus foam surfaces, reactive air surfaces versus foam surfaces, reactive water surfaces versus foam surfaces, and Nimbus versus Pegasus alternating pressure (active) air surfaces). There is also uncertainty regarding the effects of these different surfaces on the outcomes of comfort and adverse events. However, people using reactive air surfaces may be more likely to have pressure ulcers completely healed than those using foam surfaces over 37.5 days' follow-up, and reactive air surfaces may cost more for each ulcer-free day than foam surfaces. Future research in this area could consider the evaluation of alternating pressure air surfaces versus foam surfaces as a high priority. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Further review using network meta-analysis will add to the findings reported here.

Reactive air surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Reactive air surfaces (beds, mattresses or overlays) can be used for preventing pressure ulcers.

OBJECTIVES

To assess the effects of reactive air beds, mattresses or overlays compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to reactive air beds, overlays or mattresses. Comparators were any beds, overlays or mattresses that were applied for preventing pressure ulcers.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a reactive air surface was compared with surfaces that were not clearly specified, then we recorded and described the concerned study but did not included it in further data analyses.

MAIN RESULTS

We included 17 studies (2604 participants) in this review. Most studies were small (median study sample size: 83 participants). The average participant age ranged from 56 to 87 years (median: 72 years). Participants were recruited from a wide range of care settings with the majority being acute care settings. Almost all studies were conducted in the regions of Europe and America. Of the 17 included studies, two (223 participants) compared reactive air surfaces with surfaces that were not well described and therefore could not be classified. We analysed data for five comparisons: reactive air surfaces compared with (1) alternating pressure (active) air surfaces (seven studies with 1728 participants), (2) foam surfaces (four studies with 229 participants), (3) reactive water surfaces (one study with 37 participants), (4) reactive gel surfaces (one study with 66 participants), and (5) another type of reactive air surface (two studies with 223 participants). Of the 17 studies, seven (41.2%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

Pressure ulcer incidence Reactive air surfaces may reduce the proportion of participants developing a new pressure ulcer compared with foam surfaces (risk ratio (RR) 0.42; 95% confidence interval (CI) 0.18 to 0.96; I² = 25%; 4 studies, 229 participants; low-certainty evidence). It is uncertain if there is a difference in the proportions of participants developing a new pressure ulcer on reactive air surfaces compared with: alternating pressure (active) air surfaces (6 studies, 1648 participants); reactive water surfaces (1 study, 37 participants); reactive gel surfaces (1 study, 66 participants), or another type of reactive air surface (2 studies, 223 participants). Evidence for all these comparisons is of very low certainty. Included studies have data on time to pressure ulcer incidence for two comparisons. When time to pressure ulcer incidence is considered using a hazard ratio (HR), low-certainty evidence suggests that in the nursing home setting, people on reactive air surfaces may be less likely to develop a new pressure ulcer over 14 days' of follow-up than people on alternating pressure (active) air surfaces (HR 0.44; 95% CI 0.21 to 0.96; 1 study, 308 participants). It is uncertain if there is a difference in the hazard of developing new pressure ulcers between two types of reactive air surfaces (1 study, 123 participants; very low-certainty evidence). Secondary outcomes Support-surface-associated patient comfort: the included studies have data on this outcome for three comparisons. We could not pool any data as comfort outcome measures differed between included studies; therefore a narrative summary is provided. It is uncertain if there is a difference in patient comfort responses between reactive air surfaces and foam surfaces over the top of an alternating pressure (active) air surfaces (1 study, 72 participants), and between those using reactive air surfaces and those using alternating pressure (active) air surfaces (4 studies, 1364 participants). Evidence for these two comparisons is of very low certainty. It is also uncertain if there is a difference in patient comfort responses between two types of reactive air surfaces (1 study, 84 participants; low-certainty evidence). All reported adverse events: there were data on this outcome for one comparison: it is uncertain if there is a difference in adverse events between reactive air surfaces and foam surfaces (1 study, 72 participants; very low-certainty evidence). The included studies have no data for health-related quality of life and cost-effectiveness for all five comparisons.

AUTHORS' CONCLUSIONS

Current evidence is uncertain regarding any differences in the relative effects of reactive air surfaces on ulcer incidence and patient comfort, when compared with reactive water surfaces, reactive gel surfaces, or another type of reactive air surface. Using reactive air surfaces may reduce the risk of developing new pressure ulcers compared with using foam surfaces. Also, using reactive air surfaces may reduce the risk of developing new pressure ulcers within 14 days compared with alternating pressure (active) air surfaces in people in a nursing home setting. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and adjudicators of the photographs being blinded to group allocation. Further review using network meta-analysis will add to the findings reported here.

Alternative reactive support surfaces (non-foam and non-air-filled) for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Reactive surfaces that are not made of foam or air cells can be used for preventing pressure ulcers.

OBJECTIVES

To assess the effects of non-foam and non-air-filled reactive beds, mattresses or overlays compared with any other support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to non-foam or non-air-filled reactive beds, overlays or mattresses. Comparators were any beds, overlays or mattresses used.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a non-foam or non-air-filled surface was compared with surfaces that were not clearly specified, then the included study was recorded and described but not considered further in any data analyses.

MAIN RESULTS

We included 20 studies (4653 participants) in this review. Most studies were small (median study sample size: 198 participants). The average participant age ranged from 37.2 to 85.4 years (median: 72.5 years). Participants were recruited from a wide range of care settings but were mainly from acute care settings. Almost all studies were conducted in Europe and America. Of the 20 studies, 11 (2826 participants) included surfaces that were not well described and therefore could not be fully classified. We synthesised data for the following 12 comparisons: (1) reactive water surfaces versus alternating pressure (active) air surfaces (three studies with 414 participants), (2) reactive water surfaces versus foam surfaces (one study with 117 participants), (3) reactive water surfaces versus reactive air surfaces (one study with 37 participants), (4) reactive water surfaces versus reactive fibre surfaces (one study with 87 participants), (5) reactive fibre surfaces versus alternating pressure (active) air surfaces (four studies with 384 participants), (6) reactive fibre surfaces versus foam surfaces (two studies with 228 participants), (7) reactive gel surfaces on operating tables followed by foam surfaces on ward beds versus alternating pressure (active) air surfaces on operating tables and subsequently on ward beds (two studies with 415 participants), (8) reactive gel surfaces versus reactive air surfaces (one study with 74 participants), (9) reactive gel surfaces versus foam surfaces (one study with 135 participants), (10) reactive gel surfaces versus reactive gel surfaces (one study with 113 participants), (11) reactive foam and gel surfaces versus reactive gel surfaces (one study with 166 participants) and (12) reactive foam and gel surfaces versus foam surfaces (one study with 91 participants). Of the 20 studies, 16 (80%) presented findings which were considered to be at high overall risk of bias.

PRIMARY OUTCOME

Pressure ulcer incidence We did not find analysable data for two comparisons: reactive water surfaces versus foam surfaces, and reactive water surfaces versus reactive fibre surfaces. Reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds (14/205 (6.8%)) may increase the proportion of people developing a new pressure ulcer compared with alternating pressure (active) air surfaces applied on both operating tables and hospital beds (3/210 (1.4%) (risk ratio 4.53, 95% confidence interval 1.31 to 15.65; 2 studies, 415 participants; I² = 0%; low-certainty evidence). For all other comparisons, it is uncertain whether there is a difference in the proportion of participants developing new pressure ulcers as all data were of very low certainty. Included studies did not report time to pressure ulcer incidence for any comparison in this review. Secondary outcomes Support-surface-associated patient comfort: the included studies provide data on this outcome for one comparison. It is uncertain if there is a difference in patient comfort between alternating pressure (active) air surfaces and reactive fibre surfaces (one study with 187 participants; very low-certainty evidence). All reported adverse events: there is evidence on this outcome for one comparison. It is uncertain if there is a difference in adverse events between reactive gel surfaces followed by foam surfaces and alternating pressure (active) air surfaces applied on both operating tables and hospital beds (one study with 198 participants; very low-certainty evidence). We did not find any health-related quality of life or cost-effectiveness evidence for any comparison in this review.

AUTHORS' CONCLUSIONS

Current evidence is generally uncertain about the differences between non-foam and non-air-filled reactive surfaces and other surfaces in terms of pressure ulcer incidence, patient comfort, adverse effects, health-related quality of life and cost-effectiveness. Reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds may increase the risk of having new pressure ulcers compared with alternating pressure (active) air surfaces applied on both operating tables and hospital beds. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and adjudicators of the photographs being blinded to group allocation. Further review using network meta-analysis will add to the findings reported here.

Foam surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Foam surfaces (beds, mattresses or overlays) are widely used with the aim of preventing pressure ulcers.

OBJECTIVES

To assess the effects of foam beds, mattresses or overlays compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to foam beds, mattresses or overlays. Comparators were any beds, mattresses or overlays.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a foam surface was compared with surfaces that were not clearly specified, then the included study was recorded and described but not considered further in any data analyses.

MAIN RESULTS

We included 29 studies (9566 participants) in the review. Most studies were small (median study sample size: 101 participants). The average age of participants ranged from 47.0 to 85.3 years (median: 76.0 years). Participants were mainly from acute care settings. We analysed data for seven comparisons in the review: foam surfaces compared with: (1) alternating pressure air surfaces, (2) reactive air surfaces, (3) reactive fibre surfaces, (4) reactive gel surfaces, (5) reactive foam and gel surfaces, (6) reactive water surfaces, and (7) another type of foam surface. Of the 29 included studies, 17 (58.6%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

pressure ulcer incidence Low-certainty evidence suggests that foam surfaces may increase the risk of developing new pressure ulcers compared with (1) alternating pressure (active) air surfaces (risk ratio (RR) 1.59, 95% confidence interval (CI) 0.86 to 2.95; I2 = 63%; 4 studies, 2247 participants), and (2) reactive air surfaces (RR 2.40, 95% CI 1.04 to 5.54; I2 = 25%; 4 studies, 229 participants). We are uncertain regarding the difference in pressure ulcer incidence in people treated with foam surfaces and the following surfaces: (1) reactive fibre surfaces (1 study, 68 participants); (2) reactive gel surfaces (1 study, 135 participants); (3) reactive gel and foam surfaces (1 study, 91 participants); and (4) another type of foam surface (6 studies, 733 participants). These had very low-certainty evidence. Included studies have data on time to pressure ulcer development for two comparisons. When time to ulcer development is considered using hazard ratios, the difference in the risk of having new pressure ulcers, over 90 days' follow-up, between foam surfaces and alternating pressure air surfaces is uncertain (2 studies, 2105 participants; very low-certainty evidence). Two further studies comparing different types of foam surfaces also reported time-to-event data, suggesting that viscoelastic foam surfaces with a density of 40 to 60 kg/m3 may decrease the risk of having new pressure ulcers over 11.5 days' follow-up compared with foam surfaces with a density of 33 kg/m3 (1 study, 62 participants); and solid foam surfaces may decrease the risk of having new pressure ulcers over one month's follow-up compared with convoluted foam surfaces (1 study, 84 participants). Both had low-certainty evidence. There was no analysable data for the comparison of foam surfaces with reactive water surfaces (one study with 117 participants). Secondary outcomes Support-surface-associated patient comfort: the review contains data for three comparisons for this outcome. It is uncertain if there is a difference in patient comfort measure between foam surfaces and alternating pressure air surfaces (1 study, 76 participants; very low-certainty evidence); foam surfaces and reactive air surfaces (1 study, 72 participants; very low-certainty evidence); and different types of foam surfaces (4 studies, 669 participants; very low-certainty evidence). All reported adverse events: the review contains data for two comparisons for this outcome. We are uncertain about differences in adverse effects between foam surfaces and alternating pressure (active) air surfaces (3 studies, 2181 participants; very low-certainty evidence), and between foam surfaces and reactive air surfaces (1 study, 72 participants; very low-certainty evidence). Health-related quality of life: only one study reported data on this outcome. It is uncertain if there is a difference (low-certainty evidence) between foam surfaces and alternating pressure (active) air surfaces in health-related quality of life measured with two different questionnaires, the EQ-5D-5L (267 participants) and the PU-QoL-UI (233 participants). Cost-effectiveness: one study reported trial-based cost-effectiveness evaluations. Alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces in preventing pressure ulcer incidence (2029 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Current evidence suggests uncertainty about the differences in pressure ulcer incidence, patient comfort, adverse events and health-related quality of life between using foam surfaces and other surfaces (reactive fibre surfaces, reactive gel surfaces, reactive foam and gel surfaces, or reactive water surfaces). Foam surfaces may increase pressure ulcer incidence compared with alternating pressure (active) air surfaces and reactive air surfaces. Alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces in preventing new pressure ulcers. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and by blinding adjudicators of the photographs to group allocation. Further review using network meta-analysis will add to the findings reported here.

Bacteria and bioburden and healing in complex wounds: A prognostic systematic review

The wound microbiome may play an important role in the wound healing process. We conducted the first systematic prognosis review investigating whether aspects of the wound microbiome are independent prognostic factors for the healing of complex wounds. We searched Medline, Embase, CINAHL and the Cochrane Library to February 2019. We included longitudinal studies which assessed the independent association of aspects of wound microbiome with healing of complex wounds while controlling for confounding factors. Two reviewers extracted data and assessed risk of bias and certainty of evidence using the GRADE approach. We synthesised studies narratively due to the clinical and methodological heterogeneity of included studies and sparse data. We identified 28 cohorts from 21 studies with a total of 38,604 participants, including people with diabetes and foot ulcers, open surgical wounds, venous leg ulcers and pressure ulcers. Risk of bias varied from low (2 cohorts) to high (17 cohorts); the great majority of participants were in cohorts at high risk of bias. Most evidence related to the association of baseline clinical wound infection with healing. Clinical infection at baseline may be associated with less likelihood of wound healing in foot ulcers in diabetes (HR from cohort with moderate risk of bias 0.53, 95% CI 0.33 to 0.83) or slower healing in open surgical wounds (HR 0.65, 95% CI 0.51 to 0.83); evidence in other wounds is more limited. Most other associations assessed showed no clear relationship with wound healing; evidence was limited and often sparse; and we documented gaps in the evidence. There is low certainty evidence that a diagnosis of wound infection may be prognostic of poorer healing in foot ulcers in diabetes, and some moderate certainty evidence for this in open surgical wounds. Low certainty evidence means that more research could change these findings.

Compression hosiery to avoid post-thrombotic syndrome (CHAPS) protocol for a randomised controlled trial (ISRCTN73041168)

INTRODUCTION

Up to 50% of patients develop post-thrombotic syndrome (PTS) after an above knee deep vein thrombosis (DVT). The aim of the study was to determine the effect of graduated compression stockings in preventing PTS after DVT.

METHODS AND ANALYSIS

Pragmatic, UK multicentre randomised trial in adults with first above knee DVT. The standard of care arm is anticoagulation. The intervention arm will receive anticoagulation plus stockings (European class II, 23-32 mm Hg compression) worn for a median of 18 months. The primary endpoint is PTS using the Villalta score. Analysis of this will be through a time to event approach and cumulative incidence at median 6, 12 and 18 months. An ongoing process evaluation will examine factors contributing to adherence to stockings to understand if and how the behavioural interventions were effective.

ETHICS AND DISSEMINATION

UK research ethics committee approval (reference 19/LO/1585). Dissemination though the charity Thrombosis UK, the Imperial College London website, peer-reviewed publications and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN registration number 73041168.

Study protocol for a multicentre, randomised controlled trial to compare the use of the decellularised dermis allograft in addition to standard care versus standard care alone for the treatment of venous leg ulceration: DAVE trial

INTRODUCTION

Venous leg ulceration (VLU), the most common type of chronic ulcer, can be difficult to heal and is a major cause of morbidity and reduced quality of life. Although compression bandaging is the principal treatment, it is time-consuming and bandage application requires specific training. There is evidence that intervention on superficial venous incompetence can help ulcer healing and recurrence, but this is not accessible to all patients. Hence, new treatments are required to address these chronic wounds. One possible adjuvant treatment for VLU is human decellularised dermis (DCD), a type of skin graft derived from skin from deceased tissue donors. Although DCD has the potential to promote ulcer healing, there is a paucity of data for its use in patients with VLU.

METHODS AND ANALYSIS

This is a multicentre, parallel group, pragmatic randomised controlled trial. One hundred and ninety-six patients with VLU will be randomly assigned to receive either the DCD allograft in addition to standard care or standard care alone. The primary outcome is the proportion of participants with a healed index ulcer at 12 weeks post-randomisation in each treatment arm. Secondary outcomes include the time to index ulcer healing and the proportion of participants with a healed index ulcer at 12 months. Changes in quality of life scores and cost-effectiveness will also be assessed. All analyses will be carried out on an intention-to-treat (ITT) basis. A mixed-effects, logistic regression on the outcome of the proportion of those with the index ulcer healed at 12 weeks will be performed. Secondary outcomes will be assessed using various statistical models appropriate to the distribution and nature of these outcomes.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Bloomsbury Research Ethics Committee (19/LO/1271). Findings will be published in a peer-reviewed journal and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN21541209.

Characterisation of baseline microbiological and host factors in an inception cohort of people with surgical wounds healing by secondary intention reveals circulating IL-6 levels as a potential predictive biomarker of healing

Background: More than 2 million people per year are treated for surgical wounds in the UK.  Over a quarter of these wounds are estimated to heal by secondary intention (from the "bottom up") resulting in further complications and requiring increased healthcare resources. Identification of microbiological or host biomarkers that can predict healing outcomes may help to optimize the management of surgical wounds healing by secondary intention. However, the microbial and host factor heterogeneity amongst this diverse population is completely unexplored. Methods: We demonstrate feasibility of determining presence and levels of wound microbes and systemic host factors in an inception cohort of 54 people presenting with surgical wounds healing by secondary intention, who were subsequently followed-up for a period of 12-21 months. We present descriptive statistics for plasma levels of inflammatory, angiogenic cytokines and microRNAs, and we identify a range of wound colonizing microbes. We tentatively explore association with healing aiming to generate hypotheses for future research. Results: We report a potential correlation between poor healing outcomes and elevated interleukin (IL)-6 plasma levels at presentation (ρ=0.13) which requires confirmation.   Conclusions: This study demonstrates the degree of biological heterogeneity amongst people with surgical wounds healing by secondary intention and proves the feasibility of embedding a biomarker discovery study in a cohort study in surgical wounds. Our results are essential for designing large biomarker discovery studies to further investigate the potential validity of circulating IL-6 or other factors as novel predictive biomarkers of healing for surgical wounds healing by secondary intention.

Epidemiology and disease burden of complex wounds for inpatients in China: an observational study from Sichuan province

OBJECTIVES

To investigate the period prevalence of complex wounds among the overall inpatients, and the impact of complex wounds on inpatient health expense and length of hospital stay (LOS).

DESIGN

An observational study.

SETTING

6056 healthcare institutions across Sichuan province in China.

PARTICIPANTS

This study included 4 033 763 people admitted to healthcare institutions during 1 September 2018 and 31 December 2018.

RESULTS

The point prevalence of complex wounds was 4.07 per 1000 among inpatients in Sichuan. The most common complex wounds were pressure ulcers (1.47 per 1000 among inpatients). Older, male, Han ethnic groups and retired people were most likely to suffer from complex wounds. The median LOS was longer for those with complex wounds as their main condition of treatment compared with all-cause admissions in Sichuan (12 days compared with 7 days; p<0.001). The median cost of care for people with complex wounds was higher than for admission for any cause (¥6500.18 compared with ¥3337.16; p<0.001). People with pressure ulcers had the longest LOS, while people with ulcers related to diabetes incurred the highest costs.

CONCLUSIONS

Complex wounds, especially pressure ulcers, are common in Sichuan province and their presence is associated with significantly longer lengths of hospital stay and higher medical costs. Additionally, this study only included admitted inpatients during the sampling time period, hence the prevalence of complex wounds may be underestimated. The high prevalence rate and heavy direct and indirect disease burden of complex wounds indicate that health policies for early detection and prevention of complex wounds in elders are urgently needed.

Early versus deferred endovenous ablation of superficial venous reflux in patients with venous ulceration: the EVRA RCT

BACKGROUND

Venous ulceration is a common and costly health-care issue worldwide, with poor healing rates greatly affecting patient quality of life. Compression bandaging has been shown to improve healing rates and reduce recurrence, but does not address the underlying cause, which is often superficial venous reflux. Surgical correction of the reflux reduces ulcer recurrence; however, the effect of early endovenous ablation of superficial venous reflux on ulcer healing is unclear.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of compression therapy with early endovenous ablation of superficial venous reflux compared with compression therapy with deferred endovenous ablation in patients with venous ulceration.

DESIGN

A pragmatic, two-arm, multicentre, parallel-group, open randomised controlled trial with a health economic evaluation.

SETTING

Secondary care vascular centres in England.

PARTICIPANTS

Patients aged ≥ 18 years with a venous leg ulcer of between 6 weeks' and 6 months' duration and an ankle-brachial pressure index of ≥ 0.8 who could tolerate compression and were deemed suitable for endovenous ablation of superficial venous reflux.

INTERVENTIONS

Participants were randomised 1 : 1 to either early ablation (compression therapy and superficial endovenous ablation within 2 weeks of randomisation) or deferred ablation (compression therapy followed by endovenous ablation once the ulcer had healed).

MAIN OUTCOME MEASURES

The primary outcome measure was time from randomisation to ulcer healing, confirmed by blinded assessment. Secondary outcomes included 24-week ulcer healing rates, ulcer-free time, clinical success (in addition to quality of life), costs and quality-adjusted life-years (QALYs). All analyses were performed on an intention-to-treat basis.

RESULTS

A total of 450 participants were recruited (224 to early and 226 to deferred superficial endovenous ablation). Baseline characteristics were similar between the two groups. Time to ulcer healing was shorter in participants randomised to early superficial endovenous ablation than in those randomised to deferred ablation [hazard ratio 1.38, 95% confidence interval (CI) 1.13 to 1.68; p = 0.001]. Median time to ulcer healing was 56 (95% CI 49 to 66) days in the early ablation group and 82 (95% CI 69 to 92) days in the deferred ablation group. The ulcer healing rate at 24 weeks was 85.6% in the early ablation group, compared with 76.3% in the deferred ablation group. Median ulcer-free time was 306 [interquartile range (IQR) 240-328] days in the early ablation group and 278 (IQR 175-324) days in the deferred endovenous ablation group (p = 0.002). The most common complications of superficial endovenous ablation were pain and deep-vein thrombosis. Differences in repeated measures of Aberdeen Varicose Vein Questionnaire scores (p < 0.001), EuroQol-5 Dimensions index values (p = 0.03) and Short Form questionnaire-36 items body pain (p = 0.05) over the follow-up period were observed, in favour of early ablation. The mean difference in total costs between the early ablation and deferred ablation groups was £163 [standard error (SE) £318; p = 0.607]; however, there was a substantial and statistically significant gain in QALY over 1 year [mean difference between groups 0.041 (SE 0.017) QALYs; p = 0.017]. The incremental cost-effectiveness ratio of early ablation at 1 year was £3976 per QALY, with a high probability (89%) of being more cost-effective than deferred ablation at conventional UK decision-making thresholds (currently £20,000 per QALY). Sensitivity analyses using alternative statistical models give qualitatively similar results.

LIMITATIONS

Only 7% of screened patients were recruited, treatment regimens varied significantly and technical success was assessed only in the early ablation group.

CONCLUSIONS

Early endovenous ablation of superficial venous reflux, in addition to compression therapy and wound dressings, reduces the time to healing of venous leg ulcers, increases ulcer-free time and is highly likely to be cost-effective.

FUTURE WORK

Longer-term follow-up is ongoing and will determine if early ablation will affect recurrence rates in the medium and long term.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN02335796.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 24. See the NIHR Journals Library website for further project information.

The epidemiology, management and impact of surgical wounds healing by secondary intention: a research programme including the SWHSI feasibility RCT

Background

Most surgical incisions heal by primary intention (i.e. wound edges are apposed with sutures, clips or glue); however, some heal by secondary intention (i.e. the wound is left open and heals by formation of granulation tissue). There is, however, a lack of evidence regarding the epidemiology, management and impact on patients’ quality of life of these surgical wounds healing by secondary intention, resulting in uncertainty regarding effective treatments and difficulty in planning care and research.

Objectives

To derive a better understanding of the nature, extent, costs, impact and outcomes of surgical wounds healing by secondary intention, effective treatments, and the value and nature of further research.

Design

Cross-sectional survey; inception cohort; cost-effectiveness and value of implementation analyses; qualitative interviews; and pilot, feasibility randomised controlled trial.

Setting

Acute and community care settings in Leeds and Hull, Yorkshire, UK.

Participants

Adults (or for qualitative interviews, patients or practitioners) with previous experience of a surgical wound healing by secondary intention. Inclusion criteria varied between the individual workstreams.

Interventions

The pilot, feasibility randomised controlled trial compared negative-pressure wound therapy – a device applying a controlled vacuum to a wound via a dressing – with usual care (no negative-pressure wound therapy).

Results

Survey data estimated that treated surgical wounds healing by secondary intention have a point prevalence of 4.1 per 10,000 population (95% confidence interval 3.5 to 4.7 per 10,000 population). Surgical wounds healing by secondary intention most frequently occurred following colorectal surgery (n = 80, 42.8% cross-sectional survey; n = 136, 39.7% inception cohort) and were often planned before surgery (n = 89, 47.6% cross-sectional survey; n = 236, 60.1% inception cohort). Wound care was frequently delivered in community settings (n = 109, 58.3%) and most patients (n = 184, 98.4%) received active wound treatment. Cohort data identified hydrofibre dressings (n = 259, 65.9%) as the most common treatment, although 29.3% (n = 115) of participants used negative-pressure wound therapy at some time during the study. Surgical wounds healing by secondary intention occurred in 81.4% (n = 320) of participants at a median of 86 days (95% confidence interval 75 to 103 days). Baseline wound area (p ≤ 0.01), surgical wound contamination (determined during surgery; p = 0.04) and wound infection at any time (p ≤ 0.01) (i.e. at baseline or postoperatively) were found to be predictors of prolonged healing. Econometric models, using observational, cohort study data, identified that, with little uncertainty, negative-pressure wound therapy treatment is more costly and less effective than standard dressing treatment for the healing of open surgical wounds. Model A (ordinary least squares with imputation) effectiveness: 73 days longer than those who did not receive negative-pressure wound therapy (95% credible interval 33.8 to 112.8 days longer). Model A cost-effectiveness (associated incremental quality-adjusted life-years): observables –0.012 (standard error 0.005) and unobservables –0.008 (standard error 0.011). Model B (two-stage model, logistic and linear regression) effectiveness: 46 days longer than those who did not receive negative-pressure wound therapy (95% credible interval 19.6 to 72.5 days longer). Model B cost-effectiveness (associated incremental quality-adjusted life-years): observables –0.007 (standard error 0.004) and unobservables –0.027 (standard error 0.017). Patient interviews (n = 20) identified initial reactions to surgical wounds healing by secondary intention of shock and disbelief. Impaired quality of life characterised the long healing process, with particular impact on daily living for patients with families or in paid employment. Patients were willing to try any treatment promising wound healing. Health professionals (n = 12) had variable knowledge of surgical wound healing by secondary intention treatments and, frequently, favoured negative-pressure wound therapy, despite the lack of robust evidence. The pilot feasibility randomised controlled trial screened 248 patients for eligibility and subsequently recruited and randomised 40 participants to receive negative-pressure wound therapy or usual care (no negative-pressure wound therapy). Data indicated that it was feasible to complete a full randomised controlled trial to provide definitive evidence for the clinical effectiveness and cost-effectiveness of negative-pressure wound therapy as a treatment for surgical wounds healing by secondary intention. Key elements and recommendations for a larger randomised controlled trial were identified.

Limitations

This research programme was conducted in a single geographical area (i.e. Yorkshire and the Humber, UK) and local guidelines and practices may have affected treatment availability, and so may not represent UK-wide treatment choices. A wide range of wound types were included; however, some wound types may be under-represented, meaning that this research may not represent the overall surgical wound healing by secondary intention population. The lack of randomised controlled trial data on the relative effects of negative-pressure wound therapy in surgical wounds healing by secondary intention resulted in much of the economic modelling being based on observational data. Observational data, even with extensive adjustment, do not negate the potential for unresolved confounding to affect the results, which can reduce confidence in conclusions drawn from observational data. Definitive evidence from a randomised controlled trial may be the only way to overcome this lack of confidence.

Conclusions

This research has provided new information regarding the nature, extent, costs, impacts and outcomes of surgical wounds healing by secondary intention, treatment effectiveness, and the value and nature of future research, while addressing previous uncertainties regarding the problem of surgical wounds healing by secondary intention. Aspects of our research indicate that negative-pressure wound therapy is more costly and less effective than standard dressing for the healing of open surgical wounds. However, because this conclusion is based solely on observational data, it may be affected by unresolved confounding. Should a future randomised controlled trial be considered necessary, its design should reflect careful consideration of the findings of this programme of research.

Future work

This research signals the importance of further research on surgical wound healing by secondary intention. Key research questions raised by this programme of research include (1) which treatments are clinically effective and cost-effective for surgical wound healing by secondary intention for all patients or for particular patient subgroups? (2) Can particular prognostic factors predict time to healing of surgical wound healing by secondary intention? And (3) do psychosocial interventions have the potential to improve quality of life in people with hard-to-heal surgical wound healing by secondary intention? Given that negative-pressure wound therapy has been widely adopted, with relatively little evidence to support its use, the design and outcomes of a randomised controlled trial would need to be carefully considered. We focused in this research on wound healing, and maintain, based on the findings of patient interviews, that this is a key outcome for future research. Impacts of negative-pressure wound therapy on outcomes such as infection and reoperation should also be considered, as should patients’ views of the treatment. The type of patient group recruited and the outcomes of interest will all influence the duration of follow-up of any planned study. The comparator in any future study will also need careful consideration.

Trial registration

Current Controlled Trials ISRCTN12761776.

Funding

This project was funded by the National Institute for Health Research Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 8, No. 7. See the National Institute for Health Research Journals Library website for further project information.

Psychosocial and behavioural prognostic factors for diabetic foot ulcer development and healing: a systematic review

AIM

To investigate whether ulceration, amputation and healing of foot ulcers in people living with diabetes are associated with psychosocial and behavioural factors.

METHODS

We searched MEDLINE, Embase, PsychINFO, CINAHL and The Cochrane Library to March 2019 for longitudinal studies with multivariable analyses investigating independent associations. Two reviewers extracted data and assessed risk of bias.

RESULTS

We identified 15 eligible studies involving over 12 000 participants. Clinical and methodological heterogeneity precluded meta-analysis, so we summarize narratively. Risk of bias was moderate or high. For ulceration, we found significantly different results for people with and without an ulcer history. For those with no ulcer history, moderate quality evidence suggests depression increases ulcer risk [three studies; e.g. hazard ratio (HR) 1.68 (1.20, 2.35) per Hospital Anxiety and Depression Scale (HADS) standard unit]. Better foot self-care behaviour reduces ulcer risk [HR 0.61 (0.40, 0.93) per Summary of Diabetes Self-Care Activities scale standard unit; one study]. For people with diabetes and previous ulcers, low- or very low-quality evidence suggests little discernible association between ulcer recurrence and depression [e.g. HR 0.88 (0.61, 1.27) per HADS standard unit], foot self-care, footwear adherence or exercise. Low-quality evidence suggests incomplete clinic attendance is strongly associated with amputation [odds ratio (OR) 3.84 (1.54, 9.52); one study]. Evidence for the effects of other psychosocial or behavioural factors on ulcer healing and amputation is very low quality and inconclusive.

CONCLUSIONS

Psychosocial and behavioural factors may influence the development of first ulcers. More high quality research is needed on ulcer recurrence and healing. (Open Science Framework Registration: https://osf.io/ej689).

Characterisation of baseline microbiological and host factors in an inception cohort of people with surgical wounds healing by secondary intention reveals circulating IL-6 levels as a potential predictive biomarker of healing

Background: More than 2 million people per year are treated for surgical wounds in the UK.  Over a quarter of these wounds are estimated to heal by secondary intention (from the “bottom up”) resulting in further complications and requiring increased healthcare resources. Identification of microbiological or host biomarkers that can predict healing outcomes may help to optimize the management of surgical wounds healing by secondary intention. However, the microbial and host factor heterogeneity amongst this diverse population is completely unexplored. Methods: We demonstrate feasibility of determining presence and levels of wound microbes and systemic host factors in an inception cohort of 54 people presenting with surgical wounds healing by secondary intention, who were subsequently followed-up for a period of 12-21 months. We present descriptive statistics for plasma levels of inflammatory, angiogenic cytokines and microRNAs, and we identify a range of wound colonizing microbes. We tentatively explore association with healing aiming to generate hypotheses for future research. Results: We report a potential correlation between poor healing outcomes and elevated interleukin (IL)-6 plasma levels at presentation (ρ=0.13) which requires confirmation.   Conclusions: This study demonstrates the degree of biological heterogeneity amongst people with surgical wounds healing by secondary intention and proves the feasibility of embedding a biomarker discovery study in a cohort study in surgical wounds. Our results are essential for designing large biomarker discovery studies to further investigate the potential validity of circulating IL-6 or other factors as novel predictive biomarkers of healing for surgical wounds healing by secondary intention.

Nurses' and surgeons' views and experiences of surgical wounds healing by secondary intention: A qualitative study

AIMS AND OBJECTIVES

To explore surgeons' and nurses' perspectives of managing surgical wounds healing by secondary intention.

BACKGROUND

Every year, more than 10 million surgical operations are performed in the NHS in the UK. Most surgical wounds heal by primary intention, where the edges of the wound are brought together with staples, sutures, adhesive glue or clips. Sometimes wounds are deliberately left open to heal, from the base up, known as "healing by secondary intention." These wounds are often slow to heal, prone to infection and complex to manage.

DESIGN

A qualitative, descriptive approach, using semi-structured interviews.

METHODS

Interviews with five (general, vascular and plastic) surgeons and 7 nurses (3 tissue viability nurses, 2 district and 1 community nurse, and 1 hospital nurse) working in hospital and community care settings in two locations in the north of England. Data analysis followed the recommended sequential steps of "Framework" approach. Consolidated criteria for reporting qualitative research guided the study report.

RESULTS

Participants reported that the main types of wounds healing by secondary intention that they manage are extensive abdominal cavity wounds; open wounds relating to treatment for pilonidal sinus; large open wounds on the feet of patients with diabetes; and axilla and groin wounds, associated with removal of lymph nodes for cancer. Infection and prolonged time to healing were the main challenges. Negative pressure wound therapy was the most favoured treatment option.

CONCLUSIONS

Negative pressure wound therapy was advocated by professionals despite a lack of research evidence indicating clinical or cost-effectiveness. Our findings underscore the need for rigorous evaluation of negative pressure wound therapy, and other wound care treatments, through studies that include economic evaluation.

RELEVANCE FOR CLINICAL PRACTICE

Clinical decision-making in wound care could be optimised through further robust studies to inform practitioners about the cost-effectiveness of available treatments.

Use of antimicrobial dressings in England and the association with published clinical guidance: interrupted time series analysis

OBJECTIVES

In healthcare systems, practices and products of unproven value and cost-effectiveness can decrease value and increase waste. Using the management of complex wounds, this study investigates temporal trends in the use of antimicrobials dressings, places this in the context of available evidence and discusses the potential impacts on the UK National Health Service (NHS).

DESIGN

Secondary descriptive and interrupted time series (ITS) analysis of NHS prescription data.

SETTING

Prescribing Cost Analysis (PCA) details all NHS prescriptions dispensed in the community in England.

INTERVENTIONS

An ITS design was used to compare annual changes in the expenditure and use of antimicrobial and non-antimicrobial dressings before and after the publication of the 'intervention' of key evidence-based Scottish Intercollegiate Guidelines Network (SIGN) guidance in 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

Trends in use and expenditure of antimicrobial dressings in relation to published clinical guidance.

RESULTS

There was a large increase in the prescribing of, and expenditure on, antimicrobial wound dressings between 1997 and 2016. In 1997, the total number of dressings prescribed was 5 792 700; increasing to 11 447 102 in 2009 with expenditure increasing from £1 960 386 to £32 841 263. During the year of the SIGN intervention (2010), there was a significant drop in the use of silver but there was no consistent ongoing reduction from 2011 to 2015.

CONCLUSIONS

Prescribing data can be used to identify products of unproven benefit, which also impose a significant financial burden. This study quantifies the huge increase in the use of antimicrobial wound dressings over a 20-year period despite the lack of compelling evidence to support their routine use. There is some suggestion, however that the use and expenditure decreased after the publication of key guidance. Routine data can be used to as part of more systematic efforts to increase value and reduce waste in health systems.

Preventing pressure ulcers in nursing homes using a care bundle: A feasibility study

Pressure ulcers can be painful and negatively affect health-related quality of life and healthcare costs. Many people living in nursing homes are at risk of developing a pressure ulcer. Nursing home staff, tissue viability nurses and researchers have co-designed the first theory and evidence-informed care bundle specifically for nursing homes, which consists of three prevention practices (skin inspection, support surfaces, repositioning) and a range of behaviour change techniques to promote these practices. We conducted a mixed methods feasibility study of the use of this care bundle in one nursing home in the North of England using an uncontrolled, before-and-after study design. We collected quantitative data on pressure ulcer prevention behaviours of the nursing home staff and pressure ulcer incidence rates for 5 weeks prior to implementing the bundle. Data collection continued for a further 9 weeks during the bundle implementation phase. We explored adherence to the bundle and participants' experiences of using it. The Conceptual Framework for Implementation Fidelity and the Theoretical Domains Framework informed the semi-structured interviews. Quantitative and qualitative data were analysed using descriptive statistics and deductive framework analysis respectively. We collected data for 462 resident bed days prior to implementing the bundle; five new pressure ulcers were recorded and repositioning was the only documented pressure ulcer prevention behaviour. We collected data for 1,181 resident bed days during the intervention phase; no new pressure ulcers developed and the documented prevention behaviours included repositioning, skin inspection and checking support surfaces. Participants reported that the bundle enhanced the care they delivered and offered suggestions for future improvements. Our findings have highlighted a number of feasibility issues surrounding recruitment and retention, collecting data and implementation fidelity. A pressure ulcer prevention bundle specifically designed for nursing homes was acceptable. The feasibility work has highlighted the potential for the intervention and the areas that require development and refinement.

A cross-sectional survey of patients with open surgical wounds in Slovenia

Most surgical wounds heal by primary intention, that is, the wound is closed with sutures, clips, or glue. However, some surgical wounds are either left open to heal from the bottom up ("healing by secondary intention") or break open partially or fully after primary closure. There is little basic knowledge about the occurrence and natural history of surgical wounds healing by secondary intention (SWHSI); therefore, the aim of this survey was to estimate the number of people with SWHSI in Slovenia, the nature of these wounds, and to investigate how they are managed. A multiservice, cross-sectional survey was carried out over a 2-week period in the city of Ljubljana, Slovenia (population 288,919). Healthcare professionals across health and social care settings completed one anonymised form for each patient with a SWHSI. Forms were completed for 110 patients. The point prevalence of SWHSI was 0.38 per 1,000 of the population (95% CI: 0.33-0.44). Patients' mean age was 50.5 years. The majority of SWHSI were planned to heal by secondary intention before surgery (76/110, 69%). Of SWHSI, 83% (92/110) were treated with wound dressings, and 6% were treated with negative pressure wound therapy. Data were missing for 11 cases. This survey is the first to provide essential information about the extent, nature, and treatment of SWHSI in Slovenia. Furthermore, it is one of the latest of a very small number of studies to have contributed to knowledge about SWHSI globally. The results from the survey can be used for planning future research, health resources management, and policy development.

Preventing pressure injury in nursing homes: developing a care bundle using the Behaviour Change Wheel

OBJECTIVE

To develop, with nurse specialists and nursing home care staff, a theory and evidence-informed pressure injury prevention care bundle for use in nursing home settings.

DESIGN

The development of a care bundle.

METHODS

We undertook a detailed, multistaged and theoretically driven development process. First, we identified evidence-informed pressure injury prevention practices: these formed an initial set of possible target behaviours to be considered for inclusion in the bundle. During a 4-hour workshop and supplemental email consultation with a total of 13 healthcare workers, we agreed the key target behaviours for the care bundle. We explored with staff the barriers and facilitators to prevention activity and defined intervention functions and behaviour change practices using the Behaviour Change Wheel.

SETTING

North West England.

RESULTS

The target behaviours consisted of three elements: support surfaces, skin inspection and repositioning. We identified capability, opportunity and reflective motivation as influencing the pressure injury prevention behaviours of nursing home care staff. The intervention functions (education, training, modelling) and behaviour change techniques (information about social and environmental consequences, information on health consequences, feedback on behaviour, feedback on the outcome of behaviour, prompts/cues, instruction on how to perform the behaviour, demonstration of behaviour) were incorporated into the care bundle.

CONCLUSION

This is the first description of a pressure injury prevention care bundle for nursing homes developed using the Behaviour Change Wheel. Key stakeholders identified and prioritised the appropriate target behaviours to aid pressure injury prevention in a nursing home setting.

Cost-effectiveness analysis of a randomized clinical trial of early versus deferred endovenous ablation of superficial venous reflux in patients with venous ulceration

BACKGROUND

Treatment of superficial venous reflux in addition to compression therapy accelerates venous leg ulcer healing and reduces ulcer recurrence. The aim of this study was to evaluate the costs and cost-effectiveness of early versus delayed endovenous treatment of patients with venous leg ulcers.

METHODS

This was a within-trial cost-utility analysis with a 1-year time horizon using data from the EVRA (Early Venous Reflux Ablation) trial. The study compared early versus deferred endovenous ablation for superficial venous truncal reflux in patients with a venous leg ulcer. The outcome measure was the cost per quality-adjusted life-year (QALY) over 1 year. Sensitivity analyses were conducted with alternative methods of handling missing data, alternative preference weights for health-related quality of life, and per protocol.

RESULTS

After early intervention, the mean(s.e.m.) cost was higher (difference in cost per patient £163(318) (€184(358))) and early intervention was associated with more QALYs at 1 year (mean(s.e.m.) difference 0·041(0·017)). The incremental cost-effectiveness ratio (ICER) was £3976 (€4482) per QALY. There was an 89 per cent probability that early venous intervention is cost-effective at a threshold of £20 000 (€22 546)/QALY. Sensitivity analyses produced similar results, confirming that early treatment of superficial reflux is highly likely to be cost-effective.

CONCLUSION

Early treatment of superficial reflux is highly likely to be cost-effective in patients with venous leg ulcers over 1 year. Registration number: ISRCTN02335796 (http://www.isrctn.com).

Negative pressure wound therapy for treating foot wounds in people with diabetes mellitus

BACKGROUND

Foot wounds in people with diabetes mellitus (DM) are a common and serious global health issue. People with DM are prone to developing foot ulcers and, if these do not heal, they may also undergo foot amputation surgery resulting in postoperative wounds. Negative pressure wound therapy (NPWT) is a technology that is currently used widely in wound care. NPWT involves the application of a wound dressing attached to a vacuum suction machine. A carefully controlled negative pressure (or vacuum) sucks wound and tissue fluid away from the treated area into a canister. A clear and current overview of current evidence is required to facilitate decision-making regarding its use.

OBJECTIVES

To assess the effects of negative pressure wound therapy compared with standard care or other therapies in the treatment of foot wounds in people with DM in any care setting.

SEARCH METHODS

In January 2018, for this first update of this review, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies, reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. We identified six additional studies for inclusion in the review.

SELECTION CRITERIA

Published or unpublished randomised controlled trials (RCTs) that evaluated the effects of any brand of NPWT in the treatment of foot wounds in people with DM, irrespective of date or language of publication. Particular effort was made to identify unpublished studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction. Initial disagreements were resolved by discussion, or by including a third review author when necessary. We presented and analysed data separately for foot ulcers and postoperative wounds.

MAIN RESULTS

Eleven RCTs (972 participants) met the inclusion criteria. Study sample sizes ranged from 15 to 341 participants. One study had three arms, which were all included in the review. The remaining 10 studies had two arms. Two studies focused on postamputation wounds and all other studies included foot ulcers in people with DM. Ten studies compared NPWT with dressings; and one study compared NPWT delivered at 75 mmHg with NPWT delivered at 125 mmHg. Our primary outcome measures were the number of wounds healed and time to wound healing.NPWT compared with dressings for postoperative woundsTwo studies (292 participants) compared NPWT with moist wound dressings in postoperative wounds (postamputation wounds). Only one study specified a follow-up time, which was 16 weeks. This study (162 participants) reported an increased number of healed wounds in the NPWT group compared with the dressings group (risk ratio (RR) 1.44, 95% confidence interval (CI) 1.03 to 2.01; low-certainty evidence, downgraded for risk of bias and imprecision). This study also reported that median time to healing was 21 days shorter with NPWT compared with moist dressings (hazard ratio (HR) calculated by review authors 1.91, 95% CI 1.21 to 2.99; low-certainty evidence, downgraded for risk of bias and imprecision). Data from the two studies suggest that it is uncertain whether there is a difference between groups in amputation risk (RR 0.38, 95% CI 0.14 to 1.02; 292 participants; very low-certainty evidence, downgraded once for risk of bias and twice for imprecision).NPWT compared with dressings for foot ulcersThere were eight studies (640 participants) in this analysis and follow-up times varied between studies. Six studies (513 participants) reported the proportion of wounds healed and data could be pooled for five studies. Pooled data (486 participants) suggest that NPWT may increase the number of healed wounds compared with dressings (RR 1.40, 95% CI 1.14 to 1.72; I² = 0%; low-certainty evidence, downgraded once for risk of bias and once for imprecision). Three studies assessed time to healing, but only one study reported usable data. This study reported that NPWT reduced the time to healing compared with dressings (hazard ratio (HR) calculated by review authors 1.82, 95% CI 1.27 to 2.60; 341 participants; low-certainty evidence, downgraded once for risk of bias and once for imprecision).Data from three studies (441 participants) suggest that people allocated to NPWT may be at reduced risk of amputation compared with people allocated to dressings (RR 0.33, 95% CI 0.15 to 0.70; I² = 0%; low-certainty evidence; downgraded once for risk of bias and once for imprecision).Low-pressure compared with high-pressure NPWT for foot ulcersOne study (40 participants) compared NPWT 75 mmHg and NPWT 125 mmHg. Follow-up time was four weeks. There were no data on primary outcomes. There was no clear difference in the number of wounds closed or covered with surgery between groups (RR 0.83, 95% CI 0.47 to 1.47; very low-certainty evidence, downgraded once for risk of bias and twice for serious imprecision) and adverse events (RR 1.50, 95% CI 0.28 to 8.04; very low-certainty evidence, downgraded once for risk of bias and twice for serious imprecision).

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that NPWT, when compared with wound dressings, may increase the proportion of wounds healed and reduce the time to healing for postoperative foot wounds and ulcers of the foot in people with DM. For the comparisons of different pressures of NPWT for treating foot ulcers in people with DM, it is uncertain whether there is a difference in the number of wounds closed or covered with surgery, and adverse events. None of the included studies provided evidence on time to closure or coverage surgery, health-related quality of life or cost-effectiveness. The limitations in current RCT evidence suggest that further trials are required to reduce uncertainty around decision-making regarding the use of NPWT to treat foot wounds in people with DM.

Protease activity as a prognostic factor for wound healing in venous leg ulcers

BACKGROUND

Venous leg ulcers (VLUs) are a common type of complex wound that have a negative impact on people's lives and incur high costs for health services and society. It has been suggested that prolonged high levels of protease activity in the later stages of the healing of chronic wounds may be associated with delayed healing. Protease modulating treatments have been developed which seek to modulate protease activity and thereby promote healing in chronic wounds.

OBJECTIVES

To determine whether protease activity is an independent prognostic factor for the healing of venous leg ulcers.

SEARCH METHODS

In February 2018, we searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase and CINAHL.

SELECTION CRITERIA

We included prospective and retrospective longitudinal studies with any follow-up period that recruited people with VLUs and investigated whether protease activity in wound fluid was associated with future healing of VLUs. We included randomised controlled trials (RCTs) analysed as cohort studies, provided interventions were taken into account in the analysis, and case-control studies if there were no available cohort studies. We also included prediction model studies provided they reported separately associations of individual prognostic factors (protease activity) with healing. Studies of any type of protease or combination of proteases were eligible, including proteases from bacteria, and the prognostic factor could be examined as a continuous or categorical variable; any cut-off point was permitted. The primary outcomes were time to healing (survival analysis) and the proportion of people with ulcers completely healed; the secondary outcome was change in ulcer size/rate of wound closure. We extracted unadjusted (simple) and adjusted (multivariable) associations between the prognostic factor and healing.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion at each stage, and undertook data extraction, assessment of risk of bias and GRADE assessment. We collected association statistics where available. No study reported adjusted analyses: instead we collected unadjusted results or calculated association measures from raw data. We calculated risk ratios when both outcome and prognostic factor were dichotomous variables. When the prognostic factor was reported as continuous data and healing outcomes were dichotomous, we either performed regression analysis or analysed the impact of healing on protease levels, analysing as the standardised mean difference. When both prognostic factor and outcome were continuous data, we reported correlation coefficients or calculated them from individual participant data.We displayed all results on forest plots to give an overall visual representation. We planned to conduct meta-analyses where this was appropriate, otherwise we summarised narratively.

MAIN RESULTS

We included 19 studies comprising 21 cohorts involving 646 participants. Only 11 studies (13 cohorts, 522 participants) had data available for analysis. Of these, five were prospective cohort studies, four were RCTs and two had a type of case-control design. Follow-up time ranged from four to 36 weeks. Studies covered 10 different matrix metalloproteases (MMPs) and two serine proteases (human neutrophil elastase and urokinase-type plasminogen activators). Two studies recorded complete healing as an outcome; other studies recorded partial healing measures. There was clinical and methodological heterogeneity across studies; for example, in the definition of healing, the type of protease and its measurement, the distribution of active and bound protease species, the types of treatment and the reporting of results. Therefore, meta-analysis was not performed. No study had conducted multivariable analyses and all included evidence was of very low certainty because of the lack of adjustment for confounders, the high risk of bias for all studies except one, imprecision around the measures of association and inconsistency in the direction of association. Collectively the research indicated complete uncertainty as to the association between protease activity and VLU healing.

AUTHORS' CONCLUSIONS

This review identified very low validity evidence regarding any association between protease activity and VLU healing and there is complete uncertainty regarding the relationship. The review offers information for both future research and systematic review methodology.