Differences in buprenorphine initiation and retention for opioid use disorder between primary care and substance use...

Buprenorphine, an evidenced-based medication for opioid use disorder (OUD), can be prescribed in any medical setting, including primary care (PC) and substance use disorder (SUD) specialty clinics. While research has identified patient characteristics associated with buprenorphine initiation and retention within both settings, between-settings evaluations have been limited. This evaluation examined differences in patient characteristics associated with buprenorphine initiation and retention between PC and SUD settings within the Veterans Health Administration.

Retrospective cohort quality improvement evaluation of veterans with OUD with ≥2 PC visits in a 1-year period who initiated buprenorphine within one-year of initial visit in either PC or SUD settings. Mixed-effects logistic regressions examined associations between patient characteristics and initiation setting and whether associations between patient characteristics and 180-day retention differed across setting.

Of 372 patients who initiated buprenorphine in SUD clinics and 317 in PC, 47.6% and 44.3% had 180-day retention, respectively. Patients aged 35-65 (vs. < 35; adjusted odds ratio [AOR] = 3.17; 95% confidence interval [CI] = 1.56, 6.44) and 65+ (AOR = 5.37; CI = 2.32, 12.42), and married patients (AOR = 2.04; CI = 1.30, 3.19) were more likely to initiate in PC. Patients with unstable housing (AOR = 0.46; CI = 0.28, 0.76) and non-alcohol SUD (AOR = 0.42; CI = 0.27, 0.66) were less likely to initiate in PC compared to SUD clinics. Patients with PTSD were less likely to be retained in SUD clinics (AOR = 0.48; CI = 0.31, 0.75), with no significant association for PTSD in PC (AOR = 1.47; CI = 0.90, 2.38).

Findings suggest that patient characteristics associated with buprenorphine initiation may differ by health care setting. However, retention among subgroups of patients appears similar across settings.