Risk of venous thromboembolism in patients treated for bacterial infection in the community with outpatient parenteral antimicrobial therapy

Risk of venous thromboembolism in outpatient parenteral antimicrobial therapy (OPAT): A systematic review and meta-analysis

The risk of venous thromboembolism (VTE) in outpatient parenteral antimicrobial therapy (OPAT) is not fully understood and the optimal strategy for thromboprophylaxis remains unclear. This systematic review investigated the incidence of VTE in OPAT settings (PROSPERO CRD42022381523). MEDLINE, CINAHL, Emcare, Embase, Cochrane Library and grey literature were searched from earliest records to 18 January 2023. Primary studies reporting non-catheter-related VTE or catheter-related thromboembolism (CRT) events in adults who received parenteral antibiotics in home or outpatient settings were eligible. In total, 43 studies involving 23 432 patient episodes were reviewed, of which 4 studies reported non-catheter-related VTE and 39 included CRT. Based on generalised linear mixed-effects models, pooled risk estimates of non-catheter-related VTE and CRT were 0.2% [95% confidence interval (CI) 0.0-0.7%] and 1.1% [95% CI 0.8-1.5%; prediction interval (PI) 0.2-5.4%]. Heterogeneity was largely attributed to risk of bias by meta-regression (R2 = 21%). Excluding high-risk-of-bias studies, CRT risk was 0.8% (95% CI 0.5-1.2%; PI 0.1-4.5%). From 25 studies, the pooled CRT rate per 1000 catheter-days was 0.37 (95% CI 0.25-0.55; PI 0.08-1.64). These findings do not support universal thromboprophylaxis or routine use of an inpatient VTE risk assessment model in the OPAT setting. However, a high index of suspicion should be maintained, especially for patients with known risk factors for VTE. An optimised protocol of OPAT-specific VTE risk assessment should be sought.

Postoperative venous thromboembolism event increases risk of readmissions and reoperation following total joint arthroplasty: a propensity-matched cohort study

PURPOSE

The clinical impact of postoperative venous thromboembolism (VTE) following total joint arthroplasty (TJA) remains unclear. In this study, we evaluate the effect of VTE following TJA on postoperative outcomes including discharge disposition, readmission rates, and revision rates.

METHODS

We retrospectively reviewed all patients over the age of 18 who underwent primary, elective THA or TKA between 2013 and 2020. Patients were stratified into two cohorts based on whether or not they had a VTE following their procedure. Baseline patient demographics and clinical outcomes such as readmissions and revisions were collected. Propensity score matching was performed to limit significant demographic differences, while independent sample t-tests and Pearson's chi-squared test were used to compare outcomes of interest between the groups.

RESULTS

After propensity score matching, there were 109 patients in each cohort, representing a total of 218 patients for the matched comparison. Prior to matching, the VTE cohort was noted to have a significantly higher BMI than the non-VTE cohort (32.22 ± 6.27 vs 30.93 ± 32.04 kg/m², p = 0.032). All other patient demographics were similar. Compared to the non-VTE cohort, the VTE cohort was less likely to be discharged home (66.1% vs 80.7%; p = 0.021), had a higher rate of 90-day all-cause readmissions (27.5% vs 9.2%, p = 0.001), and a higher two-year revision rate (11.0% vs 0.9%, p = 0.003).

CONCLUSION

Patients with postoperative VTE were less likely to be discharged home and had higher 90-day readmission and two-year revision rates. Therefore, mitigating perioperative risk factors, initiating appropriate long-term anticoagulation, and maintaining close follow-up for patients with postoperative VTE may play significant roles in decreasing hospital costs and the economic burden to the healthcare system.

LEVEL OF EVIDENCE III

Retrospective Cohort Study.

Risk factors for catheter related thrombosis during outpatient parenteral antimicrobial therapy

BACKGROUND

Outpatient parenteral antimicrobial therapy (OPAT) delivery using peripherally inserted central catheters is associated with a risk of catheter related thrombosis (CRT). Individualised preventative interventions may reduce this occurrence, however patient selection is hampered by a lack of understanding of risk factors. We aimed to identify patient, infection or treatment related risk factors for CRT in the OPAT setting.

METHODS

Retrospective case control study (1:3 matching) within OPAT services at two tertiary hospitals within Australia.

RESULTS

Over a 2 year period, encompassing OPAT delivery to 1803 patients, there were 19 cases of CRT, giving a prevalence of 1.1% and incidence of 0.58/1000 catheter days. Amongst the cases of CRT, there were nine (47%) unplanned readmissions and two (11%) pulmonary emboli. Compared to controls, cases had a higher frequency of malposition of the catheter tip (4/19 (21%) vs 0/57 (0%), p = 0.003) and complicated catheter insertion (3/19 (16%) vs 1/57 (2%), p = 0.046).

CONCLUSIONS

Although CRTs during OPAT are infrequent, they often have clinically significant sequelae. Identification of modifiable vascular access related predictors of CRT should assist with patient risk stratification and guide risk reduction strategies.

Updated good practice recommendations for outpatient parenteral antimicrobial therapy (OPAT) in adults and children in the UK

UK good practice recommendations for outpatient parenteral antimicrobial therapy (OPAT) were published in 2012 and 2015 for adult and paediatric patients, respectively. Here we update the initial good practice recommendations in a combined document based on a further review of the OPAT literature and an extensive consultation process. As with the previous good practice recommendations, these updated recommendations are intended to provide pragmatic guidance for new and established OPAT services across a range of settings and to act as a set of quality indicators for service evaluation and quality improvement.

Clinical and cost-effectiveness, safety and acceptability of community intravenous antibiotic service models: CIVAS systematic review

OBJECTIVE

Evaluate evidence of the efficacy, safety, acceptability and cost-effectiveness of outpatient parenteral antimicrobial therapy (OPAT) models.

DESIGN

A systematic review.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Library, National Health Service (NHS) Economic Evaluation Database (EED), Research Papers in Economics (RePEc), Tufts Cost-Effectiveness Analysis (CEA) Registry, Health Business Elite, Health Information Management Consortium (HMIC), Web of Science Proceedings, International Pharmaceutical Abstracts, British Society for Antimicrobial Chemotherapy website. Searches were undertaken from 1993 to 2015.

STUDY SELECTION

All studies, except case reports, considering adult patients or practitioners involved in the delivery of OPAT were included. Studies combining outcomes for adults and children or non-intravenous (IV) and IV antibiotic groups were excluded, as were those focused on process of delivery or clinical effectiveness of 1 antibiotic over another. Titles/abstracts were screened by 1 reviewer (20% verified). 2 authors independently screened studies for inclusion.

RESULTS

128 studies involving >60 000 OPAT episodes were included. 22 studies (17%) did not indicate the OPAT model used; only 29 involved a comparator (23%). There was little difference in duration of OPAT treatment compared with inpatient therapy, and overall OPAT appeared to produce superior cure/improvement rates. However, when models were considered individually, outpatient delivery appeared to be less effective, and self-administration and specialist nurse delivery more effective. Drug side effects, deaths and hospital readmissions were similar to those for inpatient treatment, but there were more line-related complications. Patient satisfaction was high, with advantages seen in being able to resume daily activities and having greater freedom and control. However, most professionals perceived challenges in providing OPAT.

CONCLUSIONS

There were no systematic differences related to the impact of OPAT on treatment duration or adverse events. However, evidence of its clinical benefit compared with traditional inpatient treatment is lacking, primarily due to the dearth of good quality comparative studies. There was high patient satisfaction with OPAT use but the few studies considering practitioner acceptability highlighted organisational and logistic barriers to its delivery.

The Community IntraVenous Antibiotic Study (CIVAS): a mixed-methods evaluation of patient preferences for and cost-effectiveness of different service models for delivering outpatient parenteral antimicrobial therapy

Background

Outpatient parenteral antimicrobial therapy (OPAT) is widely used in most developed countries, providing considerable opportunities for improved cost savings. However, it is implemented only partially in the UK, using a variety of service models.

Objectives

The aims of this research were to (1) establish the extent of OPAT service models in England and identify their development; (2) evaluate patients’ preferences for different OPAT service delivery models; (3) assess the cost-effectiveness of different OPAT service delivery models; and (4) convene a consensus panel to consider our evidence and make recommendations.

Methods

This mixed-methods study included seven centres providing OPAT using four main service models: (1) hospital outpatient (HO) attendance; (2) specialist nurse (SN) visiting at home; (3) general nurse (GN) visiting at home; and (4) self-administration (SA) or carer administration. Health-care providers were surveyed and interviewed to explore the implementation of OPAT services in England. OPAT patients were interviewed to determine key service attributes to develop a discrete choice experiment (DCE). This was used to perform a quantitative analysis of their preferences and attitudes. Anonymised OPAT case data were used to model cost-effectiveness with both Markov and simulation modelling methods. An expert panel reviewed the evidence and made recommendations for future service provision and further research.

Results

The systematic review revealed limited robust literature but suggested that HO is least effective and SN is most effective. Qualitative study participants felt that different models of care were suited to different types of patient and they also identified key service attributes. The DCE indicated that type of service was the most important factor, with SN being strongly preferred to HO and SA. Preferences were influenced by attitudes to health care. The results from both Markov and simulation models suggest that a SN model is the optimal service for short treatment courses (up to 7 days). Net monetary benefit (NMB) values for HO, GN and SN services were £2493, £2547 and £2655, respectively. For longer treatment, SA appears to be optimal, although SNs provide slightly higher benefits at increased cost. NMB values for HO, GN, SN and SA services were £8240, £9550, £10,388 and £10,644, respectively. The simulation model provided useful information for planning OPAT services. The expert panel requested more guidance for service providers and commissioners. Overall, they agreed that mixed service models were preferable.

Limitations

Recruitment to the qualitative study was suboptimal in the very elderly and ethnic minorities, so the preferences of patients from these groups might not be represented. The study recruited from Yorkshire, so the findings may not be applicable nationally.

Conclusions

The quantitative preference analysis and economic modelling favoured a SN model, although there are differences between sociodemographic groups. SA provides cost savings for long-term treatment but is not appropriate for all.

Future work

Further research is necessary to replicate our results in other regions and populations and to evaluate mixed service models. The simulation modelling and DCE methods used here may be applicable in other health-care settings.

Funding

The National Institute for Health Research Health Service and Delivery Research programme.