The impact of benzodiazepine exposure on treatment retention in an open-access methadone program: A retrospective cohort study.

Abstract

Open-access opioid treatment programs (OTP) offer same-day access to methadone without an appointment and aim to minimize treatment barriers that often reduce admission and/or retention. We explored whether patients with benzodiazepine exposure at treatment entry would have similar 12-month retention compared to those without benzodiazepine exposure. We conducted a retrospective cohort study of 2968 patients consecutively initiated on methadone between January 2015 and February 2017 at an open-access OTP. The sample was stratified into benzodiazepine-exposed and nonexposed groups based on intake urine toxicology. Group comparison of 12-month retention was conducted. Kaplan Meier analysis compared time to methadone treatment discontinuation between groups with a log-rank test. Multivariable Cox regression was performed to compare retention by baseline benzodiazepine exposure with adjustment for confounders. Overall, 31% of patients with benzodiazepine exposure (n = 171) and 31% without exposure (n = 2423) were retained at 12 months (p = 0.95). Median treatment duration was 182 days (95% CI, 152-239) and 175 days (95% CI, 156-196) for patients with and without benzodiazepine exposure, respectively. Kaplan-Meier analysis showed no significant difference in treatment duration between groups (log-rank test p = 0.73). Cox regression found no difference in treatment retention between groups (adjusted Hazard Ratio= 1.03, 95% CI, 0.91-1.16). In this cohort of patients receiving methadone at an open-access OTP, benzodiazepine exposure at intake was not observed to impact 12-month treatment retention or duration. These findings support U.S. Food and Drug Administration (FDA) recommendations to not withhold medications for opioid use disorder from patients taking benzodiazepines.