Evaluating the Impact of Pharmacist-Based Models of Care on Treatment Retention Among Individuals With Opioid Use Disorder: A Systematic Review and Meta-Analysis

Objectives: This review aimed to evaluate the effectiveness of pharmacist-based interventions on treatment retention and nonprescribed opioid use among individuals with opioid use disorder (OUD). A secondary objective was to characterize the types of pharmacist-based interventions for treating OUD. Methods: PubMed, PsycINFO, and CINAHL were searched for records published from the inception of each database until 2025 by 2 independent reviewers. We also searched clinicaltrial.gov and Google Scholar. Eligible studies reported retention in treatment following pharmacist-based interventions for patients with OUD. We performed meta-analyses using the generic inverse variance method and random effects models to estimate the pooled retention rates and the proportion of negative urine opioid toxicology tests following pharmacist-based interventions. Results: Of 3318 records screened and 47 full‑text reviewed, 13 were included. The overall pooled retention rate following pharmacist-based intervention was 77% (pooled proportion=0.77, 95% CI: 0.67–0.87). A pooled retention rate of 76% at 6 months (pooled proportion=0.76, 95% CI: 0.63–0.90) and 59% at 1 year (pooled proportion=0.59, 95% CI: 0.50–0.68) were observed. The pooled proportion of negative urine opioid toxicology test was 84% (pooled proportion=0.84, 95% CI: 0.73–0.96). Pharmacists performed comprehensive functions, including collaborating on OUD diagnostic confirmation, prescribing, and initiating medications for OUD. Conclusions: Pharmacist-based interventions were associated with a pooled retention rate of 77% and reduced nonprescribed opioid use. Our findings underscore the value of pharmacists’ multifaceted roles and support their integration into comprehensive care models addressing OUD.