Socioeconomic marginalization and risk of overdose in a community-recruited cohort of people who use drugs: A longitudinal analysis.

Background: Poverty and socioeconomic disadvantage are important contributors to drug-related harm, but their precise role in overdose risk remains poorly understood. We sought to examine linkages between socioeconomic marginalization and non-fatal overdose risk in a community deeply affected by the ongoing drug poisoning crisis.

Methods: This observational study used data derived from two community-recruited prospective cohorts of people who use drugs (PWUD) in Vancouver, British Columbia, Canada. Generalized linear mixed-effects models were used to assess longitudinal associations between multiple dimensions of socioeconomic disadvantage and self-reported non-fatal overdose.

Results: Between 2014 and 2020, 1,493 participants (38.2% women; 59.6% white; 35.7% Indigenous) provided 9,968 interviews. Non-fatal overdose was reported by 32.5% of participants over the study period. In multivariable analyses, non-fatal overdose was independently associated with incarceration (adjusted odds ratios [AOR]: 1.42, 95% confidence interval [CI]: 1.08-1.88, p=0.012), homelessness (AOR: 1.57, 95%CI: 1.27-1.93, p<0.001), increased monthly income (AOR: 1.01, 95%CI: 1.00-1.01, p=0.029), and lower material security (AOR: 0.76, 95%CI: 0.67-0.88, p<0.001). We also observed differing strengths of association between illegal income generation and overdose in men (AOR: 1.84, 95%CI: 1.46-2.32, p<0.001) compared to women (AOR: 1.37, 95%CI: 1.06-1.78, p=0.016).

Conclusion: Non-fatal overdose was positively associated with incarceration, homelessness, higher monthly income, material insecurity, and engagement illegal income generating activities, underscoring the importance of addressing the socioeconomic production of overdose risk. These initiatives may include supportive housing interventions, alternative economic supports, and broader drug policy reform.