Systematic Review and Meta-Analysis to Estimate the Burden of Non-Fatal and Fatal Overdose Among People Who Inject Drugs Living in the United States and Comparator Countries: 2010 – 2023

BACKGROUND: People who inject drugs (PWID) have high risk for overdose, but there are no current estimates of overdose rates in this population. We aimed to estimate rates of non-fatal and fatal overdose among PWID living in the United States (US) and comparator countries (Canada, Mexico, United Kingdom, Australia), and ratios of non-fatal to fatal overdose rates, using literature published 01/01/2010 - 09/29/2023. METHODS: PubMed, PsycINFO, Embase, and ProQuest databases were systematically searched to identify publications reporting prevalence or rates of recent 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 a quality assessment tool, and heterogeneity was explored using sensitivity analyses. RESULTS: Our review included 143 studies, with 58 contributing unique data to the meta-analysis. Non-fatal and fatal overdose rates among PWID in the US were 32.9 per 100 person-years (PY) (95% CI: 26.4-40.9) and 1.7 per 100 PY (95% CI: 0.9-3.2), respectively. Post-2016 data yielded a non-fatal overdose rate of 41.0 per 100 PY (95% CI: 32.1-52.5) and a fatal overdose rate of 2.5 per 100 PY (95% CI: 1.4-4.3) in the US. An estimated 5% of overdoses among PWID in the US and Canada resulted in death during 2010-2023, compared to 6% in the UK and 2% in Australia. CONCLUSION: Findings demonstrate substantial burden of non-fatal and fatal overdose among PWID in the US and some comparator countries. Scale-up of interventions to prevent overdose mortality are urgently needed.