Outcomes of Methadone and Buprenorphine Maintenance Treatments in Opioid Use Disorder Patients: A Retrospective Cohort Study Publisher Pubmed



Akbarzadeh I ; Gholami J ; Rahimi Movaghar A ; Yaseri M ; Noroozi A ; Ardeshir M ; Yazdani K
Source: Substance Use and Misuse Published:2026

Abstract

Aim: This study aimed to examine the retention and urine test results among patients undergoing methadone maintenance treatments (MMT) and buprenorphine maintenance treatments (BMT) in Iran. Methods: A retrospective cohort study was conducted on individuals with opioid use disorders who initiated MMT and BMT at the clinic of the Iranian National Center for Addiction Studies between 2015 and 2019. First-episode treatment data were extracted from patients’ treatment records, with an 18-month follow-up period. Baseline characteristics, retention, and urine test results were analyzed. Factors associated with retention were assessed using the accelerated failure time (AFT) survival model, and urine test changes were evaluated using a mixed-effects model. Results: Of 341 patients, 210 (61.58%) were in the MMT group, and 131 (38.41%) were in the BMT group, with 97.6 and 93.9% males, respectively. The mean ages were 41.2 ± 11.7 for MMT and 37.4 ± 11.0 for BMT. Median treatment durations were 66.5 days for MMT and 45 days for BMT. Retention proportions at 3, 6, and 12 months were 47, 37, and 26% for MMT and 35, 21, and 14% for BMT, respectively. Positive urine test results decreased by 44% (from 51 to 7%, p < .05) after 12 months of treatment. The multivariable AFT model showed that MMT was associated with significantly longer retention compared to BMT (adjusted time ratio: 1.55, 95%CI 1.04–2.62, p < .05). Conclusion: Enhancing the quality of opioid agonist treatment services is essential to improve patient retention. © 2026 Taylor & Francis Group, LLC.