Prevalence and risk factors for opioid overdose among women: A systematic review and meta-analysis

Background: North America, Australia and parts of Europe have experienced recent increases in opioid overdoses. As most overdoses occur in men, less attention has focused on overdoses among women. To address this, we conducted a systematic review to examine the prevalence of opioid overdoses and to identify gender-specific risk factors. Methods: We searched five databases and included all RCTs and observational studies of adults (aged ≥18 years) where opioid overdose data were reported by gender. Data were extracted on the proportions and rates of fatal or non-fatal opioid overdose among women across different opioid types, and gender specific risk factors relating to opioid overdose. Meta-analyses were conducted to estimate the prevalence of fatal and non-fatal overdoses among women. NHMRC levels of evidence were documented for each study. Prospective registration was completed in PROSPERO (CRD2021227833). Results: In total, 124 studies were included, of which 69 were included in 10 meta-analyses. Overall, 30 % (95 %CI:28 %-32 %) of fatal overdoses and 44 % (95 %CI:36 %-51 %) of non-fatal overdoses were among women. Overdose rates for intentional self-harm, repeated overdose and community correction populations were higher among women, compared to men. Age and belonging to racial minorities were associated with increased opioid overdose risk among women. Conclusion: The prevalence of opioid overdoses varies greatly among women by subpopulation and opioid type. Overdose is generally less common among women compared to men, yet where intentional self-harm or repeated overdose occurs, and among community correction populations, women comprise the majority of overdoses. Tailored interventions could specifically target these highest risk populations.