Pathways of care following opioid overdose among people with opioid use disorder: a multilevel cohort study

Background — The care that people with opioid use disorder (OUD) receive during hospitalizations for opioid overdoses present opportunities for support, yet initiation of opioid agonist treatment (OAT) remains low. Therefore, we sought to determine factors associated with treatment initiation following hospitalization for an opioid overdose.

Methods — We conducted a population-based cohort study of people with OUD discharged from hospital following an opioid overdose between January 1, 2014 and December 31, 2021 in Ontario, Canada. Our primary outcome was initiation of treatment (OAT and/or safer opioid supply) within 30 days of discharge. Proportional hazards frailty models were used to account for the clustering of hospital and geographic-level variables with cause-specific hazards ratios calculated for each factor.

Results — Overall, 13,253 individuals experienced 22,848 opioid overdoses and were discharged from 175 hospitals across Ontario. Treatment was initiated in 10.3 % of opioid overdoses. Person-related variables associated with treatment initiation included hepatitis C diagnoses (HR=1.15, 95 % CI=1.01–1.30) and public drug benefit eligibility (HR=1.50, 95 % CI=1.36–1.66). Longer stays in hospital were also associated with a significant increase in treatment initiation over the first 10 days of follow-up only (HR=1.10 per 5 days in hospital; 95 % CI=1.06–1.15). People discharged from regions with the highest quantile of fatal opioid overdose rates had an increased hazard of treatment initiation (HR=1.26; 95 % CI=1.06–1.51), compared to regions in the lowest quantile.

Conclusion — The identification of factors associated with treatment initiation following overdose may be associated with promoting longer stays in hospital and enhancing accessibility in regions with less experience managing opioid overdoses.