Methods
treatment-emergent adverse, OUD
SECONDARY
This was a secondary analysis of a randomized, double-blind, placebo-controlled study in which adults with moderate or severe OUD received monthly injections of BUP-XR (2 × 300-mg doses, then 4 × 100-mg or 300-mg maintenance doses) or placebo for 24 weeks. Abstinence was defined as opioid-negative urine drug screens combined with negative self-reports collected weekly. Each participant’s percentage abstinence was calculated after the first, second, and third maintenance doses in opioid-injecting and non-injecting participants. The proportion of participants achieving opioid abstinence in each group was also calculated weekly. Treatment retention rate following the first maintenance dose was estimated for opioid-injecting participants with Kaplan–Meier method. Risk-adjusted comparisons were made via inverse propensity weighting using propensity scores. Buprenorphine plasma concentration–time profiles were compared between injecting and non-injecting participants. The percentages of participants reporting treatment-emergent adverse events were compared between maintenance dose groups within injecting and non-injecting participants separately.