Access to Mental Health and Substance Use Treatment in Comprehensive Primary Care Plus.

To meet increasing demand for mental health and substance use services, the Centers for Medicare & Medicaid Services launched the 5-year Comprehensive Primary Care Plus (CPC+) demonstration in 2017, requiring primary care practices to integrate behavioral health services. To examine the association of CPC+ with access to mental health and substance use treatment before and during the COVID-19 pandemic. Using difference-in-differences analyses, this retrospective cohort study compared adults attributed to CPC+ and non-CPC+ practices, from January 1, 2018, to June 30, 2022. The study included adults aged 19 to 64 years who had depression, anxiety, or opioid use disorder (OUD) and were enrolled with a private health insurer in Pennsylvania. Data were analyzed from January to June 2023. Receipt of care at a practice participating in CPC+. Total cost of care and the number of primary care visits for evaluation and management, community mental health center visits, psychiatric hospitalizations, substance use treatment visits (residential and nonresidential), and prescriptions filled for antidepressants, anxiolytics, buprenorphine, naltrexone, or methadone. The 188 770 individuals in the sample included 102 733 adults (mean [SD] age, 49.5 [5.6] years; 57 531 women [56.4%]) attributed to 152 CPC+ practices and 86 037 adults (mean [SD] age, 51.6 [6.6] years; 47 321 women [54.9%]) attributed to 317 non-CPC+ practices. Among patients diagnosed with OUD, compared with patients attributed to non-CPC+ practices, attribution to a CPC+ practice was associated with filling more prescriptions for buprenorphine (0.117 [95% CI, 0.037 to 0.196] prescriptions per patient per quarter) and anxiolytics (0.162 [95% CI, 0.005 to 0.319] prescriptions per patient per quarter). Among patients diagnosed with depression or anxiety, attribution to a CPC+ practice was associated with more prescriptions for buprenorphine (0.024 [95% CI, 0.006 to 0.041] prescriptions per patient per quarter). Findings of this cohort study suggest that individuals with an OUD who received care at a CPC+ practice filled more buprenorphine and anxiolytics prescriptions compared with patients who received care at a non-CPC+ practice. As the Centers for Medicare & Medicaid Innovation invests in advanced primary care demonstrations, it is critical to understand whether these models are associated with indicators of high-quality primary care.