Systematic review and meta-analysis to estimate the burden of non-fatal and fatal overdose among people who inject drugs living in the U.S. and comparator countries: 2010 - 2023.

BackgroundPeople who inject drugs (PWID) have high risk for overdose, but there are no current estimates of overdose rates in this population. We estimated the rates of non-fatal and fatal overdose among PWID living in the U.S. and comparator countries (Canada, Mexico, United Kingdom, Australia), and ratios of non-fatal to fatal overdose, using literature published 01/01/2010 - 09/29/2023. MethodsPubMed, PsychInfo, Embase, and ProQuest databases were systematically searched to identify publications reporting prevalence or rates of recent (past 12 months) non- fatal and fatal overdose among PWID. Non-fatal and fatal overdose rates were meta-analyzed using random effects models. Risk of bias was assessed using an adapted quality assessment tool, and heterogeneity was explored using sensitivity analyses. ResultsOur review included 143 records, with 58 contributing unique data to the meta- analysis. Non-fatal and fatal overdose rates among PWID in the U.S. were 32.9 per 100 person- years (PY) (95% CI: 26.4 - 40.9; n=28) and 1.7 per 100 PY (95% CI: 0.9 - 3.2; n=4), respectively. Limiting the analysis to data collected after 2016 yielded a non-fatal rate of 41.0 per 100 PY (95% CI: 32.1 - 52.5; n=16) and a fatal rate of 2.5 per 100 PY (95% CI: 1.4 - 4.3; n=2) in the U.S. An estimated 5% of overdoses among PWID in the U.S. result in death. Among the analyzed countries, Australia had the lowest non-fatal and fatal overdose rates and the largest ratio of non-fatal to fatal overdose. ConclusionFindings demonstrate substantial burden of non-fatal and fatal overdose among PWID in the U.S. and comparator countries. Scale-up of interventions that prevent overdose mortality and investments in PWID health research are urgently needed.