INTRODUCTION: Non-fatal opioid overdose (NFOD) is a concerning public health issue that is a risk factor for subsequent fatal overdose.

METHODS: This systematic review aimed to evaluate all the previous literature using a self-report method to investigate the risk factors of NFOD. The Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRSIMA) and its 27-item checklist guided the conduct and reporting of this systematic review. The review used the population, risk factor, and outcome (PRO) framework. The population was studies with a majority of participants that regularly used opioids. Risk factors were demographic, medical, and behavioral characteristics. The outcomes were self-reported recent (<12 months) or lifetime presence of NFOD. The study explored seven databases: PubMed, Embase, Cochrane Library, PsycINFO, CINAHL, ProQuest, and Web of Science and used Google Scholar to search for grey literature. A risk of bias assessment was carried out using ROBANS-E and meta-analysis was performed using STATA.

RESULTS: The review discovered 53 studies using the self-report experience of persons who use opioids assessing different factors associated with NFOD. Involvement in the sex trade, having a lower than typical education, previous incarceration, experiencing homelessness, unemployment, psychiatric co-morbidity, suicidal ideation or behavior, polysubstance use, especially benzodiazepine use and problematic alcohol use, needing help injecting, former opioid agonist therapy (OAT) engagement, previous treatment experiences, and a hepatitis-C diagnosis were associated with an increased likelihood of NFOD. Current engagement in OAT was protective against NFOD. Gender, relationship status, needle exchange use, symptoms of anxiety, and being HIV positive were not strongly associated with a difference in NFOD likelihood.

CONCLUSION: Using the findings from above to identify the individuals who are at high risk for NFOD, particularly those using opioids, will enable a targeted approach to outreach and education programs based on the identified risk factors- such as polysubstance use, socioeconomic associations, and psychiatric co-morbidities, which can help reduce the occurrence of NFOD.