Medication for Opioid Use Disorder After Opioid Overdose Is Associated With Reduced Mortality

Non-fatal opioid overdose is a major risk factor for fatal overdose and medication for opioid use disorder (MOUD) may reduce that risk. This study used data from multiple Massachusetts administrative systems (2011-2015) to create a retrospective cohort of overdose survivors (N=17,568), document the risk of subsequent fatal overdose, and assess the association between the receipt of MOUD and mortality. Criteria defining the index non-fatal overdose were validated, and for the main analysis, deaths occurring in the last month of MOUD and the month after MOUD were attributed to the medication.

• In the 12 months prior to the index overdose, 26% of individuals had any MOUD; 41% were prescribed opioids, 28% were prescribed benzodiazepines, and 22% had a detoxification admission.
• For the 12 months after the index overdose, the all-cause death rate was 4.7 per 100 patient-years and the opioid-related death rate was 2.1 per 100 patient-years. Seventeen percent of cases received buprenorphine for a median of 4 months, 11% received methadone for a median of 5 months, and 6% received naltrexone for a median of 1 month.
• Compared with no MOUD, the adjusted hazard ratio for all-cause mortality was 0.47 for methadone, 0.63 for buprenorphine, and 1.44 (but non-significant) for naltrexone. Similar hazard ratios were found for opioid-related mortality. In a secondary analysis in which deaths were only attributable to MOUD during the month MOUD was received, there was a two-thirds reduction in death.

Comments: Survivors of opioid overdose who receive medical attention have extremely high one-year mortality, and although methadone and buprenorphine are both strongly associated with reduced risk of death, less than one-third of patients received any MOUD in the year following non-fatal overdose. Selection bias is unlikely to account for such a striking reduction in mortality. Data were limited for naltrexone, with fewer cases treated, very short treatment duration, and no association with reduced mortality. Addressing the opioid crisis will require changes in systems of care to increase engagement and retention of high-risk groups in MOUD treatment.

Joseph Merrill, MD, MPH

Reference: Larochelle MR, Bernson D, Land T, et al. Medication for opioid use disorder after nonfatal opioid overdose and association with mortality: a cohort study. Ann Intern Med. 2018;169(3):137–145.