Elevated prevalence of self-reported unintentional exposure to fentanyl among women who use drugs in a Canadian setting: A cross-sectional analysis

Background: The United States and Canada are in the midst of an overdose epidemic, fueled by illicitly manufactured fentanyl. While marked differences in vulnerability to drug-related harm between men and women who use drugs is well characterized, the extent to which gender differences manifest in the present overdose crisis remains understudied. We examined differences in self-reported unintentional exposure to fentanyl between men and women who use drugs. Methodology: Data were derived from three prospective cohorts of people who use drugs in Vancouver, Canada. Survey data were extracted on individuals who self-reported having used drugs known or believed to contain fentanyl in the past 30 days between December 2016 and November 2017. We used multivariable logistic regression (MLR) to examine the relationship between self-identified gender (woman vs. man) and self-reported unintentional exposure to fentanyl. As a sub-analysis, correlates of self-reported unintentional exposure to fentanyl were identified using MLR, stratified by gender. Results: Of 578 eligible participants, including 219 (37.9%) women, 200 (33.2%) perceived their exposure to fentanyl as unintentional (40.2% among women and 29.0% among men). In the MLR, being a woman was positively associated with self-reported unintentional fentanyl exposure (adjusted odds ratio = 2.11; 95% confidence interval: 1.45-3.09). Among women at least daily heroin use was negatively associated with self-reported unintentional fentanyl exposure, while perceiving a high or moderate risk of overdosing on fentanyl was positively associated with outcome. Among men older age was positively associated with self-reported unintentional fentanyl exposure, while injection drug use and at least daily heroin use was negatively associated with the outcome (all p<0.05). Conclusions: Women were more than two times as likely to self-report they were unintentionally exposed to fentanyl compared to men. These findings highlight the urgent need to further understand experiences of gender-based risk differences and develop gender-focused interventions and policies aimed at preventing drug-related harm.