Predictors of medication-assisted treatment initiation for opioid use disorder in an interdisciplinary primary care model

Introduction: Medication-assisted treatment (MAT) for opioid use disorder (OUD) is underused in primary care. Little is known about patient demographics associated with MAT initiation, particularly among models with an interdisciplinary approach, including behavioral health integration. We hypothesize few disparities in MAT initiation by patient characteristics after implementing this model for OUD. Methods: Electronic health record data were used to identify adults with >1 primary care visit in 1 of 2 study clinics in a Pacific Northwest academic health system between September 1, 2015 and August 31, 2017 (n = 23,372). Rates of documented OUD diagnosis were calculated. Multivariate logistic regression estimated odds ratios of MAT initiation, defined as >1 electronic health record order for buprenorphine or naltrexone, by patient covariates. Results: Seven percent of the study sample had an OUD diagnosis. Of those patients, 32% had >1 MAT order. Patients with documented psychiatric diagnoses or tobacco use had higher odds of initiating MAT (odds ratio [OR] = 1.62, P = .0003; OR = 2.46, P < .0001, respectively). Uninsured, Medicaid, and Medicare patients had lower odds than those commercially insured (OR = 0.53, 0.38, and 0.31, respectively; P < .0001). Patients who were older, of a race/ethnicity other than non-Hispanic white, had documented diabetes, and had documented asthma or chronic obstructive pulmonary disease showed lower odds of initiation. Discussion: MAT initiation varied by patient characteristics, including disparities by insurance coverage and race/ethnicity. The addition of behavioral health did not eliminate disparities in care, but higher odds of initiation among those with a documented psychiatric diagnosis may suggest this model reaches some vulnerable populations. Additional research is needed to further examine these findings.