Exploring the effect of implementation and context on a stepped-wedge randomised controlled trial of a vital sign triage device in routine maternity care in low-resource settings

Midwife-led obstetric triage to increase providers' knowledge and improve timeliness of care: A pre and posttest design

BACKGROUND

Research in low- and middle-income countries has shown that maternal mortality is directly related to inadequate or absent obstetric (OB) triage systems. Standard triage systems and knowledge on triaging for obstetric emergencies are often absent or lacking in most healthcare systems in Liberia.

OBJECTIVE

The objective of this research was to address the third delay defined as receiving adequate, quality care when a facility is reached by increasing knowledge through the establishment of a midwife-led, hospital-based OB triage system to stratify care based on risk and imminence of birth and to improve timely assessment at two district referral hospitals.

METHODS

A quasi-experimental study design using a pre/post survey was employed for a midwife-led OB triage training course. Using a train-the-trainer model, five midwives were trained as champions, who in turn trained an additional 62 providers. Test results were analyzed with the R statistical software using paired sample t-test and descriptive statistics.

RESULTS

Pretest results revealed a knowledge and practice gap among OB providers on key components of the standard triage package. However, post-test mean scores were significantly higher (M = 79.6, SD = 2.32) than pre-test mean scores (M = 59.0, SD = 2.30) for participants following a 2-day training (p = <0.001).

DISCUSSION

Following a structured OB triage training, participants showed significant improvement in post-test OB triage scores.

CONCLUSION

Standard OB triage protocols incorporated into the policies and procedures of obstetric wards have the potential to improve knowledge and practice, addressing the third delay and reducing preventable, obstetrics-related deaths.

Thermal Imaging for Burn Wound Depth Assessment: A Mixed-Methods Implementation Study

Background: Implementing innovations emerging from clinical research can be challenging. Thermal imagers provide an accessible diagnostic tool to increase the accuracy of burn wound depth assessment. This mixed-methods implementation study aimed to assess the barriers and facilitators, design implementation strategies, and guide the implementation process of thermal imaging in the outpatient clinic of a burn centre. Methods: This study was conducted between September 2022 and February 2023 in Beverwijk, The Netherlands. Semi-structured interviews with burn physicians guided by the Consolidated Framework for Implementation Research (CFIR) were conducted to identify barriers and facilitators. Based on the barriers, implementation strategies were developed with the CFIR-ERIC Matching Tool, and disseminated to support the uptake of the thermal imager. Subsequently, thermal imaging was implemented in daily practice, and an iterative RE-AIM approach was used to evaluate the implementation process. Results: Common facilitators for the implementation of the thermal imager were the low complexity, the relative advantage above other diagnostic tools, and benefits for patients. Common barriers were physicians' attitude towards and perceived value of the intervention, the low compatibility with the current workflow, and a lack of knowledge about existing evidence. Six implementation strategies were developed: creating a formal implementation blueprint, promoting adaptability, developing educational materials, facilitation, conducting ongoing training, and identifying early adopters. These strategies resulted in the effective implementation of the thermal imager, reflected by a >70% reach among eligible patients, and >80% effectiveness and adoption. Throughout the implementation process, compatibility, and available resources remained barriers, resulting in low ratings on RE-AIM dimensions. Conclusions: This study developed implementation strategies based on the identified CFIR constructs that impacted the implementation of a thermal imager for burn wound assessment in our outpatient clinic. The experiences and findings of this study could be leveraged to guide the implementation of thermal imaging and other innovations in burn care.

CRADLE-5: a stepped-wedge type 2 hybrid implementation-effectiveness cluster randomised controlled trial to evaluate the real-world scale-up of the CRADLE Vital Signs Alert intervention into routine maternity care in Sierra Leone-study protocol

BACKGROUND

The CRADLE Vital Signs Alert intervention (an accurate easy-to-use device that measures blood pressure and pulse with inbuilt traffic-light early warning system, and focused training package) was associated with reduced rates of eclampsia and maternal death when trialled in urban areas in Sierra Leone. Subsequently, implementation was successfully piloted as evidenced by measures of fidelity, feasibility and adoption. The CRADLE-5 trial will examine whether national scale-up, including in the most rural areas, will reduce a composite outcome of maternal and fetal mortality and maternal morbidity and will evaluate how the CRADLE package can be embedded sustainably into routine clinical pathways.

METHODS

CRADLE-5 is a stepped-wedge cluster-randomised controlled trial of the CRADLE intervention compared to routine maternity care across eight rural districts in Sierra Leone (Bonthe, Falaba, Karene, Kailahun, Koinadugu, Kono, Moyamba, Tonkolili). Each district will cross from control to intervention at six-weekly intervals over the course of 1 year (May 2022 to June 2023). All women identified as pregnant or within six-weeks postpartum presenting for maternity care in the district are included. Primary outcome data (composite rate of maternal death, stillbirth, eclampsia and emergency hysterectomy) will be collected. A mixed-methods process and scale-up evaluation (informed by Medical Research Council guidance for complex interventions and the World Health Organization ExpandNet tools) will explore implementation outcomes of fidelity, adoption, adaptation and scale-up outcomes of reach, maintenance, sustainability and integration. Mechanisms of change and contextual factors (barriers and facilitators) will be assessed. A concurrent cost-effectiveness analysis will be undertaken.

DISCUSSION

International guidance recommends that all pregnant and postpartum women have regular blood pressure assessment, and healthcare staff are adequately trained to respond to abnormalities. Clinical effectiveness to improve maternal and perinatal health in more rural areas, and ease of integration and sustainability of the CRADLE intervention at scale has yet to be investigated. This trial will explore whether national scale-up of the CRADLE intervention reduces maternal and fetal mortality and severe maternal adverse outcomes and understand the strategies for adoption, integration and sustainability in low-resource settings. If successful, the aim is to develop an adaptable, evidence-based scale-up roadmap to improve maternal and infant outcomes.

TRIAL REGISTRATION

ISRCTN 94429427. Registered on 20 April 2022.

Scale-up of a novel vital signs alert device to improve maternity care in Sierra Leone: a mixed methods evaluation of adoption

BACKGROUND

The CRADLE (Community blood pressure monitoring in Rural Africa: Detection of underLying pre-Eclampsia) Vital Signs Alert device-designed specifically to improve maternity care in low resource settings-had varying impact when trialled in different countries. To better understand the contextual factors that may contribute to this variation, this study retrospectively evaluated the adoption of CRADLE, during scale-up in Sierra Leone.

METHODS

This was a mixed methods study. A quantitative indicator of adoption (the proportion of facilities trained per district) was calculated from existing training records, then focus groups were held with 'CRADLE Champions' in each district (n = 32), to explore adoption qualitatively. Template Analysis was used to deductively interpret qualitative data, guided by the NASSS (non-adoption, abandonment, scale-up, spread, sustainability) Framework.

FINDINGS

Substantial but non-significant variation was found in the proportion of facilities trained in each district (range 59-90%) [X² (7, N = 8) = 10.419, p = 0.166]. Qualitative data identified complexity in two NASSS domains that may have contributed to this variation: 'the technology' (for example, charging issues, difficulty interpreting device output and concerns about ongoing procurement) and 'the organisation' (for example, logistical barriers to implementing training, infighting and high staff turnover). Key strategies mentioned to mitigate against these issues included: transparent communication at all levels; encouraging localised adaptations during implementation (including the involvement of community leaders); and selecting Champions with strong soft skills (particularly conflict resolution and problem solving).

CONCLUSIONS

Complexity related to the technology and the organisational context were found to influence the adoption of CRADLE in Sierra Leone, with substantial inter-district variation. These findings emphasise the importance of gaining an in-depth understanding of the specific system and context in which a new healthcare technology is being implemented. This study has implications for the ongoing scale-up of CRADLE, and for those implementing or evaluating other health technologies in similar contexts.

A continuity of care programme for women at risk of preterm birth in the UK: Process evaluation of a hybrid randomised controlled pilot trial

BACKGROUND

The development and evaluation of specific maternity care packages designed to address preterm birth remains a public health priority. We aim to evaluate the implementation, context, and potential mechanisms of action, of a new care pathway that combined midwifery continuity of care with a specialist obstetric clinic for women at risk of preterm birth (POPPIE) in London (UK).

METHODS

We did a multiphase mixed method triangulation evaluation nested within a hybrid type 2, randomised controlled trial in London (United Kingdom). Pregnant women with identified risk factors for preterm birth were eligible for trial participation and randomly assigned (1:1) to either midwifery continuity of care linked to a specialist obstetric clinic (POPPIE group) or standard maternity care. The primary outcome was a composite of appropriate and timely interventions for the prevention and/or management of preterm labour and birth, analysed according to intention to treat. Clinical and process outcome data were abstracted from medical records and electronic data systems, and coded by study team members, who were masked to study group allocation. Implementation data were collected from meeting records and key documents, postnatal surveys (n = 164), semi-structured interviews with women (n = 30), healthcare providers and stakeholders (n = 24) pre-, mid and post implementation. Qualitative and quantitative data from meeting records and key documents were examined narratively. Qualitative data from interviews were analysed using three thematic frameworks: Proctor's (for implementation outcomes: appropriateness, adoption, feasibility, acceptability, fidelity, penetration, sustainability), the Consolidated Framework for Implementation Research (for determinants of implementation), and published program theories of continuity models (for potential mechanisms). Data triangulation followed a convergent parallel and pragmatic approach which brought quantitative and qualitative data together at the interpretation stage. We averaged individual implementation measures across all domains to give a single composite implementation strength score which was compared to the primary outcome.

RESULTS

Between May 9, 2017, and Sep 30, 2018, 553 women were assessed for eligibility and 334 were enrolled with less than 6% of loss to follow up (169 were assigned to the POPPIE group; 165 were to the standard group). There was no difference in the primary outcome (POPPIE group 83·3% versus standard group 84·7%; risk ratio 0·98 [95% CI 0·90 to 1·08]). Appropriateness and adoption: The introduction of the POPPIE model was perceived as a positive fundamental change for local maternity services. Partnership working and additional funding were crucial for adoption. Fidelity: More than 75% of antenatal and postnatal visits were provided by a named or partner midwife, and a POPPIE midwife was present in more than 80% of births. Acceptability: Nearly 98% of women who responded to the postnatal survey were very satisfied with POPPIE model. Quantitative fidelity and acceptability results were supported by the qualitative findings. Penetration and sustainability: Despite delays (likely associated with lack of existing continuity models at the hospital), the model was embedded within established services and a joint decision was made to sustain and adapt the model after the trial (strongly facilitated by national maternal policy on continuity pathways). Potential mechanisms of impact identified included e.g. access to care, advocacy and perceptions of safety and trust. There was no association between implementation measures and the primary outcome.

CONCLUSIONS

The POPPIE model of care was a feasible and acceptable model of care that was implemented with high fidelity and sustained in maternity services. Larger powered trials are feasible and needed in other settings, to evaluate the impact and implementation of continuity programmes in other communities affected by preterm birth and women who experience social disadvantage and vulnerability.

TRIAL REGISTRATION

UKCRN Portfolio Database (prospectively registered, 24 April 2017): 31951. ISRCTN registry (retrospectively registered, 21 August 2017): ISRCTN37733900.

Effect of the Growth Assessment Protocol on the DEtection of Small for GestatioNal age fetus: process evaluation from the DESiGN cluster randomised trial

Background

Reducing the rate of stillbirth is an international priority. At least half of babies stillborn in high-income countries are small for gestational-age (SGA). The Growth Assessment Protocol (GAP), a complex antenatal intervention that aims to increase the rate of antenatal detection of SGA, was evaluated in the DESiGN type 2 hybrid effectiveness-implementation cluster randomised trial (n = 13 clusters). In this paper, we present the trial process evaluation.

Methods

A mixed-methods process evaluation was conducted. Clinical leads and frontline healthcare professionals were interviewed to inform understanding of context (implementing and standard care sites) and GAP implementation (implementing sites). Thematic analysis of interview text used the context and implementation of complex interventions framework to understand acceptability, feasibility, and the impact of context. A review of implementing cluster clinical guidelines, training and maternity records was conducted to assess fidelity, dose and reach.

Results

Interviews were conducted with 28 clinical leads and 27 frontline healthcare professionals across 11 sites. Staff at implementing sites generally found GAP to be acceptable but raised issues of feasibility, caused by conflicting demands on resource, and variable beliefs among clinical leaders regarding the intervention value. GAP was implemented with variable fidelity (concordance of local guidelines to GAP was high at two sites, moderate at two and low at one site), all sites achieved the target to train > 75% staff using face-to-face methods, but only one site trained > 75% staff using e-learning methods; a median of 84% (range 78–87%) of women were correctly risk stratified at the five implementing sites. Most sites achieved high scores for reach (median 94%, range 62–98% of women had a customised growth chart), but generally, low scores for dose (median 31%, range 8–53% of low-risk women and median 5%, range 0–17% of high-risk women) were monitored for SGA as recommended.

Conclusions

Implementation of GAP was generally acceptable to staff but with issues of feasibility that are likely to have contributed to variation in implementation strength. Leadership and resourcing are fundamental to effective implementation of clinical service changes, even when such changes are well aligned to policy mandated service-change priorities.

Trial registration

Primary registry and trial identifying number: ISRCTN 67698474. Registered 02/11/16. 10.1186/ISRCTN67698474.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13012-022-01228-1.

Physiological track-and-trigger/early warning systems for use in maternity care

BACKGROUND

A considerable challenge for maternity care providers is recognising clinical deterioration early in pregnant women. Professional bodies recommend the use of clinical assessment protocols or evaluation tools, commonly referred to as physiological track-and-trigger systems (TTS) or early warning systems (EWS), as a means of helping maternity care providers recognise actual or potential clinical deterioration early. TTS/EWS are clinician-administered (midwife, obstetrician), bedside physiological assessment protocols, charts or tools designed to record routinely assessed clinical parameters; that is, blood pressure, temperature, heart rate, urine output and mental/neurological alertness. In general, these systems involve the application of scores or alert indicators to the observed physiological parameters based on their prespecified limits of normality. The overall system score or alert limit is then used to assist the maternity care provider identify a need to escalate care. This, in turn, may allow for earlier intervention(s) to alter the course of the emerging critical illness and ultimately reduce or avoid mortality and morbidity sequelae.

OBJECTIVES

To evaluate the clinical- and cost-effectiveness of maternal physiological TTS/EWS on pregnancy, labour and birth, postpartum (up to 42 days) and neonatal outcomes.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (28 May 2021), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 June 2021), OpenGrey, the ProQuest Dissertations and Theses database (7 June 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials (RCTs), including cluster-RCTs, comparing physiological TTS/EWS with no system or another system. Participants were women who were pregnant or had given birth within the previous 42 days, at high risk and low risk for pregnancy, labour and birth, and postpartum complications.

DATA COLLECTION AND ANALYSIS

Two review authors (VS and MN) independently assessed all identified papers for inclusion and performed risk of bias assessments. Any discrepancies were resolved through discussion and consensus. Data extraction was also conducted independently by two review authors (VS and MN) and checked for accuracy. We used the summary odds ratio (OR) with 95% confidence intervals (CIs) to present the results for dichotomous data and the mean difference (MD) with 95% CI to present the results for continuous data.

MAIN RESULTS

We included two studies, a parallel RCT involving 700 women and a stepped-wedge cluster trial involving 536,233 women. Both studies were published in 2019, and both were conducted in low-resource settings. The interventions were the 'Saving Mothers Score' (SMS) and the CRADLE Vital Sign Alert (VSA) device, and both interventions were compared with standard care. Both studies had low or unclear risk of bias on all seven risk of bias criteria. Evidence certainty, assessed using GRADE, ranged from very low to moderate certainty, mainly due to other bias as well as inconsistency and imprecision. For women randomised to TTS/EWS compared to standard care there is probably little to no difference in maternal death (OR 0.80, 95% CI 0.30 to 2.11; 1 study, 536,233 participants; moderate-certainty evidence). Use of TTS/EWS compared to standard care may reduce total haemorrhage (OR 0.36, 95% CI 0.19 to 0.69; 1 study, 700 participants; low-certainty evidence). For women randomised to TTS/EWS compared to standard care there may be little to no difference in sepsis (OR 0.21, 95% CI 0.02 to 1.80; 1 study, 700 participants; low-certainty evidence), eclampsia (OR 1.50, 95% CI 0.74 to 3.03; 2 studies, 536,933 participants; low-certainty evidence) and HELLP (OR 0.21, 95% CI 0.01 to 4.40; 1 study, 700 participants; very low-certainty evidence), and probably little to no difference in maternal admission to the intensive care unit (ICU) (OR 0.78, 95% CI  0.53 to 1.15; 2 studies, 536,933 participants; moderate-certainty evidence). Use of TTS/EWS compared to standard care may reduce a woman's length of hospital stay (MD -1.21, 95% CI -1.78 to -0.64; 1 study, 700 participants; low-certainty evidence) but may result in little to no difference in neonatal death (OR 1.06, 95% CI 0.62 to 1.84; 1 study, 700 participants; low-certainty evidence). Cost-effectiveness measures were not measured in either of the two studies.  AUTHORS' CONCLUSIONS: Use of TTS/EWS in maternity care may be helpful in reducing some maternal outcomes such as haemorrhage and maternal length of hospital stay, possibly through early identification of clinical deterioration and escalation of care. The evidence suggests that the use of TTS/EWS compared to standard care probably results in little to no difference in maternal death and may result in little to no difference in neonatal death. Both of the included studies were conducted in low-resource settings where the use of TTS/EWS might potentially confer a different effect to TTS/EWS use in high-resource settings. Further high-quality trials in high- and middle-resource settings, as well as in discrete populations of high- and low-risk women, are required.

Why do strategies to strengthen primary health care succeed in some places and fail in others? Exploring local variation in the effectiveness of a community health worker managed digital health intervention in rural India

Introduction

Digital health interventions (DHIs) have huge potential as support modalities to identify and manage cardiovascular disease (CVD) risk in resource-constrained settings, but studies assessing them show modest effects. This study aims to identify variation in outcomes and implementation of SMARTHealth India, a cluster randomised trial of an ASHA-managed digitally enabled primary healthcare (PHC) service strengthening strategy for CVD risk management, and to explain how and in what contexts the intervention was effective.

Methods

We analysed trial outcome and implementation data for 18 PHC centres and collected qualitative data via focus groups with ASHAs (n=14) and interviews with ASHAs, PHC facility doctors and fieldteam mangers (n=12) Drawing on principles of realist evaluation and an explanatory mixed-methods design we developed mechanism-based explanations for observed outcomes.

Results

There was substantial between-cluster variation in the primary outcome (overall: I²=62.4%, p<=0.001). The observed heterogeneity in trial outcomes was not attributable to any single factor. Key mechanisms for intervention effectiveness were community trust and acceptability of doctors’ and ASHAs’ new roles, and risk awareness. Enabling local contexts were seen to evolve over time and in response to the intervention. These included obtaining legitimacy for ASHAs’ new roles from trusted providers of curative care; ASHAs’ connections to community and to qualified providers; their responsiveness to community needs; and the accessibility, quality and appropriateness of care provided by higher level medical providers, including those outside of the implementing (public) subsystem.

Conclusion

Local contextual factors were significant influences on the effectiveness of this DHI-enabled PHC service strategy intervention. Local adaptions need to be planned for, monitored and responded to over time. By identifying plausible explanations for variation in outcomes between clusters, we identify potential strategies to strengthen such interventions.

Distribution of hygiene kits during a cholera outbreak in Kasaï-Oriental, Democratic Republic of Congo: a process evaluation

Background

Cholera remains a leading cause of infectious disease outbreaks globally, and a major public health threat in complex emergencies. Hygiene kits distributed to cholera case-households have previously shown an effect in reducing cholera incidence and are recommended by Médecins Sans Frontières (MSF) for distribution to admitted patients and accompanying household members upon admission to health care facilities (HCFs).

Methods

This process evaluation documented the implementation, participant response and context of hygiene kit distribution by MSF during a 2018 cholera outbreak in Kasaï-Oriental, Democratic Republic of Congo (DRC). The study population comprised key informant interviews with seven MSF staff, 17 staff from other organisations and a random sample of 27 hygiene kit recipients. Structured observations were conducted of hygiene kit demonstrations and health promotion, and programme reports were analysed to triangulate data.

Results and conclusions

Between Week (W) 28-48 of the 2018 cholera outbreak in Kasaï-Oriental, there were 667 suspected cholera cases with a 5% case fatality rate (CFR). Across seven HCFs supported by MSF, 196 patients were admitted with suspected cholera between W43-W47 and hygiene kit were provided to patients upon admission and health promotion at the HCF was conducted to accompanying household contacts 5-6 times per day. Distribution of hygiene kits was limited and only 52% of admitted suspected cholera cases received a hygiene kit. The delay of the overall response, delayed supply and insufficient quantities of hygiene kits available limited the coverage and utility of the hygiene kits, and may have diminished the effectiveness of the intervention. The integration of a WASH intervention for cholera control at the point of patient admission is a growing trend and promising intervention for case-targeted cholera responses. However, the barriers identified in this study warrant consideration in subsequent cholera responses and further research is required to identify ways to improve implementation and delivery of this intervention.

Setting and techniques for monitoring blood pressure during pregnancy

BACKGROUND

Regular blood pressure (BP) measurement is crucial for the diagnosis and management of hypertensive disorders in pregnancy, such as pre-eclampsia. BP can be measured in various settings, such as conventional clinics or self-measurement at home, and with different techniques, such as using auscultatory or automated BP devices. It is important to understand the impact of different settings and techniques of BP measurement on important outcomes for pregnant women.

OBJECTIVES

To assess the effects of setting and technique of BP measurement for diagnosing hypertensive disorders in pregnancy on subsequent maternal and perinatal outcomes, women's quality of life, or use of health service resources.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) on 22 April 2020, and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving pregnant women, using validated BP devices in different settings or using different techniques.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data, assessed risk of bias, and used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

Of the 21 identified studies, we included three, and excluded 11; seven were ongoing. Of the three included RCTs (536,607 women), one was a cluster-RCT, with a substantially higher number of participants (536,233 deliveries) than the other two trials, but did not provide data for most of our outcomes. We generally judged the included studies at low risk of bias, however, the certainty of the evidence was low, due to indirectness and imprecision. Meta-analysis was not possible because each study investigated a different comparison. None of the included studies reported our primary outcome of systolic BP greater than or equal to 150 mmHg. None of the studies reported any of these important secondary outcomes: antenatal hospital admissions, neonatal unit length of stay, or neonatal endotracheal intubation and use of mechanical ventilation. Setting of BP measurement: self-measurement versus conventional clinic measurement (one study, 154 women) There were no maternal deaths in either the self-monitoring group or the usual care group. The study did not report perinatal mortality. Self-monitoring may lead to slightly more diagnoses of pre-eclampsia compared with usual care (risk ratio (RR) 1.49, 95% confidence interval (CI) 0.87 to 2.54; 154 women; 1 study; low-certainty evidence) but the wide 95% CI is consistent with possible benefit and possible harm. Self-monitoring may have little to no effect on the likelihood of induction of labour compared with usual care (RR 1.09, 95% CI 0.82 to 1.45; 154 women; 1 study; low-certainty evidence). We are uncertain if self-monitoring BP has any effect on maternal admission to intensive care (RR 1.54, 95% CI 0.06 to 37.25; 154 women; 1 study; low-certainty evidence), stillbirth (RR 2.57, 95% CI 0.13 to 52.63; 154 women; 1 study; low-certainty evidence), neonatal death (RR 1.54, 95% CI 0.06 to 37.25; 154 women; 1 study; low-certainty evidence) or preterm birth (RR 1.15, 95% CI 0.37 to 3.55; 154 women; 1 study; low-certainty evidence), compared with usual care because the certainty of evidence is low and the 95% CI is consistent with appreciable harms and appreciable benefits. Self-monitoring may lead to slightly more neonatal unit admissions compared with usual care (RR 1.53, 95% CI 0.65 to 3.62; 154 women; 1 study; low-certainty evidence) but the wide 95% CI includes the possibility of slightly fewer admissions with self-monitoring. Technique of BP measurement: Korotkoff phase IV (K4, muffling sound) versus Korotkoff phase V (K5, disappearance of sound) to represent diastolic BP (one study, 220 women) There were no maternal deaths in either the K4 or K5 group. There may be little to no difference in the diagnosis of pre-eclampsia between using K4 or K5 for diastolic BP (RR 1.16; 95% CI 0.89 to 1.49; 1 study; 220 women; low-certainty evidence), since the wide 95% CI includes the possibility of more diagnoses with K4. We are uncertain if there is a difference in perinatal mortality between the groups because the quality of evidence is low and the 95% CI is consistent with appreciable harm and appreciable benefit (RR 1.14, 95% CI 0.16 to 7.92; 1 study, 220 women; low-certainty evidence). The trial did not report data on maternal admission to intensive care, induction of labour, stillbirth, neonatal death, preterm birth, or neonatal unit admissions. Technique of BP measurement: CRADLE intervention (CRADLE device, a semi-automated BP monitor with additional features, and an education package) versus usual care (one study, 536,233 deliveries) There may be little to no difference between the use of the CRADLE device and usual care in the number of maternal deaths (adjusted RR 0.80, 95% CI 0.30 to 2.11; 536,233 women; 1 study; low-certainty evidence), but the 95% CI is consistent with appreciable harm and appreciable benefit. The trial did not report pre-eclampsia, induction of labour, perinatal mortality, preterm birth, or neonatal unit admissions. Maternal admission to intensive care and perinatal outcomes (stillbirths and neonatal deaths) were only collected for a small proportion of the women, identified by an outcome not by baseline characteristics, thereby breaking the random allocation. Therefore, any differences between the groups could not be attributed to the intervention, and we did not extract data for these outcomes.

AUTHORS' CONCLUSIONS

The benefit, if any, of self-monitoring BP in hypertensive pregnancies remains uncertain, as the evidence is limited to one feasibility study. Current practice of using K5 to measure diastolic BP is supported for women with pregnancy hypertension. The benefit, if any, of using the CRADLE device to measure BP in pregnancy remains uncertain, due to the limitations and instability of the trial study design.