Abstract
INTRODUCTION: Opioid-involved overdose mortality is a persistent public health challenge, yet limited evidence exists on the relationship between opioid use disorder treatment after a nonfatal overdose and subsequent overdose death. METHODS: National Medicare data were used to identify adult (aged 18-64 years) disability beneficiaries who received inpatient or emergency treatment for nonfatal opioid-involved overdose in 2008-2016. Opioid use disorder treatment was defined as (1) buprenorphine, measured using medication days' supply, and (2) psychosocial services, measured as 30-day exposures from and including each service date. Opioid-involved overdose fatalities were identified in the year after nonfatal overdose using linked National Death Index data. Cox proportional hazards models estimated the associations between time-varying treatment exposures and overdose death. Analyses were conducted in 2022. RESULTS: The sample (N=81,616) was mostly female (57.3%), aged ≥50 years (58.8%), and White (80.9%), with a significantly elevated overdose mortality rate, compared with the general U.S. population (standardized mortality ratio=132.4, 95% CI=129.9, 135.0). Only 6.5% of the sample (n=5,329) had opioid use disorder treatment after the index overdose. Buprenorphine (n=3,774, 4.6%) was associated with a significantly lower risk of opioid-involved overdose death (adjusted hazard ratio=0.38, 95% CI=0.23, 0.64), but opioid use disorder-related psychosocial treatment (n=2,405, 2.9%) was not associated with risk of death (adjusted hazard ratio=1.18, 95% CI=0.71, 1.95). CONCLUSIONS: Buprenorphine treatment after nonfatal opioid-involved overdose was associated with a 62% reduction in the risk of opioid-involved overdose death. However, fewer than 1 in 20 individuals received buprenorphine in the subsequent year, highlighting a need to strengthen care connections after critical opioid-related events, particularly for vulnerable groups.