Despite these limitations, our study was strengthened by its repeated-event, case-control design, allowing for reduction of selection and sampling bias stemming from conventional observational study recruitment. In addition, we controlled for conditions leading to alcohol-related events via adjustment for medications commonly found in association with such events. The protective associations of buprenorphine, methadone, and naltrexone were not significantly changed in the adjusted analyses, providing evidence of robustness to measured confounders.
