"Our finding that MOUD [Medication for Opioid Use Disorder] treatment with naltrexone was not protective against overdose or serious opioid-related acute care use is consistent with other studies15,35 that found naltrexone to be less effective than MOUD treatment with buprenorphine. The mean (SD) treatment duration for naltrexone in this cohort was longer than prior observational studies at 74.41 (70.15) days.

"Our results demonstrate the importance of treatment retention with MOUD [Medication for Opioid Use Disorder]. Individuals who received methadone or buprenorphine for longer than 6 months experienced fewer overdose events and serious opioid-related acute care use compared with those who received shorter durations of treatment or no treatment. These findings are consistent with prior research11,15,27-29 demonstrating high rates of recurrent opioid use if MOUD treatment is discontinued prematurely. Despite the benefit of MOUD in our study, treatment duration was relatively short.

"In 2016 only 13.8 percent of substance use treatment programs accepted Medicare and offered an FDA-approved medication for opioid use disorder treatment (exhibit 1). While the percentage of programs that offered such treatment was low across all insurance types (24.8 percent among programs that accepted Medicaid and 28.6 percent among programs that accepted private insurance), access for Medicare beneficiaries was nearly twice as limited.

"Our results on the cost-effectiveness of diacetylmorphine are consistent with those of an economic analysis based on data from two Dutch heroin-assisted treatment trials,²¹ despite differences in the design of the Dutch trials and the North American Opiate Medication Initiative, and the time horizon and analytic design of the economic analyses.