Collaborative Care for Opioid Use Disorder in Primary Care: A Hybrid Type 2 Cluster Randomized Clinical Trial.

Importance: The criterion-standard treatment for opioid use disorder (OUD) is medications for OUD (MOUD). However, less than a quarter of people with OUD receive MOUD. The collaborative care model (CCM) is an evidence-based practice that integrates mental and physical health treatment in primary care settings. Expanding CCM to include patients with OUD could improve MOUD initiation. Objective: To compare the effectiveness of CCM for OUD and co-occurring mental health symptoms (intervention) with CCM for mental health symptoms only (active control). Design, Setting, and Participants: This hybrid type 2a trial cluster-randomized 24 US primary care clinics to intervention or control. Participants included patients with OUD and mental health symptoms who were not receiving specialty mental health care or specialty substance use treatment. Study data were analyzed from February 2024 to January 2025. Interventions: The control care team included primary care practitioners, care managers, and psychiatric consultants. Primary care practitioners prescribed psychotropic medications with psychiatric consultation. Care manager activities included patient education, engagement and self-management, shared decision-making, measurement-based care for mental health symptoms, and brief psychotherapy for mental health. The intervention had the same components as the control, with additional MOUD training and psychiatric consultation for primary care practitioners, measurement-based care for OUD, and brief psychotherapy for OUD. Main Outcomes and Measures: Participants completed research assessments at baseline, 3 months, and 6 months. The multiple primary outcomes were past-month number of days of using opioids and the Veterans RAND 12 Mental Health Component Summary score. Results: A total of 254 patients (mean [SD] age, 40.9 [12.4] years; 139 women [59.9%]) participated in the trial. Most participants (172 of 212 [81.1%]) were taking MOUD at baseline. Days using opioids decreased in both the control and intervention groups. The intervention significantly reduced opioid use more than the control with a medium effect size (adjusted ratio of odds ratio, 0.10; 95% CI, 0.03-0.38; Cohen d = -0.44; P < .001). Mental Health Component Summary scores improved slightly in both the control and intervention groups. The intervention did not significantly improve scores more than control (adjusted difference in change, -1.20; 95% CI, -4.97 to 2.57; Cohen d = -0.09; P = .53). Conclusions and Relevance: Findings of this cluster randomized clinical trial indicate that OUD can be successfully managed in primary care with CCM, especially CCM for OUD and mental health symptoms. Primary care clinics with MOUD prescribers should consider implementing CCM for OUD and mental health. Trial Registration: ClinicalTrials.gov Identifier: NCT04600414.