Reducing disparities in alcohol use disorder treatment in underserved areas - PROJECT SUMMARY/ABSTRACT Reducing the prevalence of alcohol use disorder (AUD) is a public health priority in the US as highlighted in Healthy People 2030. Although pharmacological and behavioral treatments can reduce alcohol-related harms, a large unmet need for AUD treatment exists. The unmet need can be attributed to several factors, including the ongoing shortage of mental health workforce. In 2022, over 148 million (45%) of Americans resided in mental health professional shortage areas (MHPSAs), facing barriers to access to AUD treatment. To attract more clinicians to MHPSAs, policymakers have launched many programs, including the National Health Service Corps (NHSC). Since 2009, federal investment in the NHSC has experienced a significant surge, resulting in the NHSC clinician workforce more tripling by 2022. Compared with other types of NHSC clinicians (e.g., primary and dental care clinicians), the NHSC mental health workforce experienced the largest growth since 2009. However, no study to date has evaluated the potential effect of the NHSC expansion on disparities in AUD treatment across geographic areas. We hypothesized that the substantial growth of mental health workforce brought about by the NHSC expansion reduced disparities in AUD treatment and outcomes between MHPSAs and other areas. Further, we posited that the effects of the NHSC expansion on AUD treatment disparities differ by population groups and clinician types given the facts that people with lower socio-economic status dominated MHPSAs and that the growth of the NHSC’s workforce varied by clinician type (e.g., psychiatrists, clinical psychologists, clinical social workers, and clinical counselors). This proposed project will examine these hypotheses and fill the gap in the literature. Specifically, the project aims to assess the effect of the NHSC expansion on disparities in AUD mortality, unmet need for AUD treatment, and utilization and costs of alcohol-related emergency department visits and hospitalizations. In addition to geographic disparities between MHPSAs and non-shortage areas, the project will examine effect heterogeneity of the NHSC expansion across population groups and clinician types. We will use multiple large, national data files. To analyze the data, we will take two complementary approaches, including a difference-in- differences method and an instrumental variable approach, to generate rigorous quasi-experimental evidence about the impact of the NHSC expansion on AUD treatment disparities. By focusing on health workforce issues in underserved areas, the proposed study is highly relevant to NIAAA’s PAR-23-185, which lists workforce-related barriers to access to AUD treatment as a specific area of interest. The study findings will have important implications for policy decisions related to future directions for the NHSC and further reducing disparities in AUD treatment and outcomes.