A Realist Review of How Community-Based Drug Checking Services Could Be Designed and Implemented to Promote Engagement of People Who Use Drugs.

With rising numbers of drug-related deaths in the UK and globally, exploration of interventions that seek to reduce drug-related harm is essential. Drug checking services (DCS) allow people to submit drug samples for chemical analysis and receive feedback about the sample, as well as harm reduction advice. The use of DCS is often linked to festival and/or nightlife settings and to so-called 'recreational' drug use, but research has also shown the potential of community-based DCS as an intervention serving more varied demographics of people who use drugs, including more marginalised individuals and those experiencing drug dependence. Whilst there is a growing evidence base on the effectiveness of drug checking as a harm reduction intervention, there is still limited evidence of the underlying mechanisms and processes within DCS which may aid implementation and subsequent engagement of people who use drugs. This presents a challenge to understanding why engagement differs across types of DCS, and how best to develop and deliver services across different contexts and for different populations. To explore the contexts and mechanisms which impact engagement in community-based DCS, a realist review was undertaken to synthesise the international evidence for the delivery and implementation of DCS. There were 133 sources included in the review. From these sources the underlying contexts, mechanisms, and outcomes relating to DCS implementation and engagement were developed and refined into seven programme theories. The findings of this review are theoretically novel and hold practical relevance for the design of DCS, with implications for optimisation, tailoring, and implementing services to reach individuals in different settings.

Tranexamic acid is associated with less blood transfusion in off-pump coronary artery bypass graft surgery: a systematic review and meta-analysis.

OBJECTIVE: Tranexamic acid reduces blood loss and transfusion in on-pump coronary artery bypass graft (CABG) surgery. Compared with on-pump, off-pump surgery is associated with less blood loss and transfusion. Therefore, tranexamic acid may be less effective for off-pump surgery, and its safety profile may be different in this setting. The aim of this study was to determine the efficacy and safety of tranexamic acid for off-pump CABG surgery. DESIGN: Systematic review and meta-analysis. SETTING: University of Edinburgh. INTERVENTIONS: The administration of tranexamic acid. METHODS: A systematic review of randomized controlled trials administering tranexamic acid to patients undergoing off-pump CABG surgery. A meta-analysis of 24-hour blood loss, postoperative allogeneic transfusion, and thromboembolic events. MEASUREMENTS AND MAIN RESULTS: Eight trials were identified. The lack of appropriate data limited the meta-analysis on blood loss. Tranexamic acid significantly reduced the overall risk of allogeneic blood component transfusion (risk ratio = 0.47; 95% confidence intervals, 0.33-0.66; p < 0.0001) and packed red blood cell transfusions (risk ratio = 0.51; 95% CI, 0.36-0.71; p = 0.0001). No association was found between tranexamic acid and myocardial infarction, stroke, or pulmonary embolism. Population sizes of meta-analyses ranged from 466 to 544. CONCLUSIONS: Tranexamic acid reduces blood transfusion after off-pump surgery. Although no association with adverse events was found, the population sample size was too small to detect rare but clinically significant adverse events. A well-designed randomized controlled trial with an appropriate sample size is required to confirm tranexamic acid effectiveness and safety in off-pump CABG surgery.

A systematic review and meta-analysis of the prevalence of take-home naloxone (THN) ownership and carriage.

BACKGROUND: Drug-related deaths globally are increasing year on year, with the largest proportion of these being opioid-related. The opioid antagonist naloxone distributed for take-home use ('Take-Home Naloxone (THN)') has been championed as one method of tackling this public health crisis, however to be effective it must be available at an opioid overdose. Ownership and carriage are therefore fundamental to THN success. This study aimed to assess the prevalence of ownership and carriage of THN internationally among people who use drugs (PWUD). METHODS: NHS Scotland Journals, AMED, EMBASE, HMIC, MEDLINE, PsycINFO, CINAHL Complete, PubMed, Cochrane Library, PROSPERO and grey literature were searched for articles which measured prevalence of THN ownership or carriage between 1996 and 2020. Ownership was defined as report of a personal supply of THN. Carriage was defined as the participant carrying THN on their person at time of data collection or reporting a frequency of how often they carry THN. Risk of bias was evaluated using the Joanna Briggs Checklist for Prevalence Studies. RESULTS: Systematic search yielded 6363 papers, with ten eligible papers identified. Eight articles were included in ownership prevalence and five articles included for carriage prevalence, with an overlap of three studies between both measures. Pooled prevalence indicated moderate ownership levels (57%, CI 47-67%) but lower carriage levels (20%, CI 12-31%). Analysis was complicated by the limited number of available studies and lack of standardised terminology and measurement. CONCLUSION: Understanding naloxone ownership and carriage globally is hampered by limited evidence and heterogeneity across studies. From the available data, prevalence of THN carriage overall appears low, despite moderate ownership. Given the variation across studies, future research should seek to utilise more standardised terminology and methods of measurement. Furthermore, services distributing THN must ensure the importance of regular carriage of naloxone is consistently emphasised.