RESUMO
BACKGROUND AND AIM: Buprenorphine (BUP) maintenance treatment for opioid use disorder (OUD) begins with supervised daily dosing. We estimated the clinical effectiveness of a novel incentivised medication adherence and abstinence monitoring protocol in BUP maintenance to enable contingent access to increasing take-home medication supplies. DESIGN: Two-arm, single-centre, pragmatic, randomised controlled trial of outpatient BUP maintenance, with during-treatment follow-ups at 4 weeks, 8 weeks, 12 weeks and 16 weeks. SETTING: Inpatient and outpatient addictions treatment centre in the United Arab Emirates. PARTICIPANTS: Adults with OUD, voluntarily seeking treatment. INTERVENTIONS: The experimental condition was 16 weeks BUP maintenance with incentivised adherence and abstinence monitoring (I-AAM) giving contingent access to 7-day, then 14-day, then 21-day and 28-day medication supply. The control, treatment-as-usual (TAU) was 16 weeks BUP maintenance, with contingent access to 7-day then 14-day supply. MEASUREMENTS: The primary outcome was number of negative urine drug screens (UDS) for opioids, with non-attendance or otherwise missed UDS, imputed as positive for opioids. The secondary outcome was retention in treatment (continuous enrolment to the 16-week endpoint). FINDINGS: Of 182 patients screened, 171 were enrolled and 141 were randomly assigned to I-AAM (70 [49.6%]) and to TAU (71 [50.4%]. Follow-up rates at 4 weeks, 8 weeks, 12 weeks and 16 weeks were 91.4%, 85.7%, 71.0%, 60.0% respectively in I-AAM and 84.5%, 83.1%, 69.0%, 56.3% in TAU. By intention-to-treat, the absolute difference in percentage negative UDS for opioids was 76.7% (SD = 25.0%) in I-AAM versus 63.5% (SD = 34.7%) in TAU (mean difference = 13.3%; 95% CI = 3.2%-23.3%; Cohen's d = 0.44; 95% CI = 0.10-0.87). In I-AAM, 40 participants (57.1%) were retained versus 33 (46.4%) in TAU (odds ratio = 1.54; 95% CI = 0.79-2.98). CONCLUSIONS: Buprenorphine maintenance with incentivised therapeutic drug monitoring to enable contingent access to increasing take-home medication supplies increased abstinence from opioids compared with buprenorphine maintenance treatment-as-usual, but it did not appear to increase treatment retention.