PROJECT SUMMARY/ABSTRACT The proposed K01 award provides Dr. Downing, a new Assistant Professor in the Oregon Health & Science University/Portland State University School of Public Health, with the training and skills needed to achieve their long-term goal of becoming an independent investigator focused on the prevention and treatment of substance use disorders (SUD) among transgender and gender non-conforming (trans) people. Trans people face unique challenges related to SUD prevention and treatment, including lower healthcare access resulting from the failure of healthcare payers to cover medically necessary, trans-specific care. Dr. Downing’s background in health policy, gender and sexual minority population health, and quantitative methods in addition to their lived experience as a gender minority person makes them uniquely qualified to make significant contributions to this field. There are three areas where additional training will improve their ability to achieve their long-term career goals: 1) the financing and care delivery of state Medicaid programs, 2) the epidemiology and treatment of SUD, and 4) qualitative and mixed methods research. Dr. Downing’s training goals will be achieved through coursework, directed readings, one-on-one meetings with mentors, and mentored research activities. The K01 mentored research mixed-methods study will identify risk factors for SUD and facilitators of treatment among trans people in Oregon’s Medicaid program. The first aim of this proposal is to identify predictors of SUDs and overdose among trans people. The second aim is to identify predictors of substance use treatment among trans people with a history of a substance use disorder. The third aim proposes to understand mechanisms by which screening and treatment for SUD among trans people occur by conducting interviews with trans people and providers who serve this patient population. This proposal is highly innovative because it: 1) provides the first representative estimates of SUD and treatment among trans people enrolled in Medicaid, 2) employs a quasi-experimental approach to evaluate the impact of insurance coverage of gender-affirming care on SUD; and 3) uses a mixed methods approach to provide context for findings. This training will expand the candidate’s ability to conduct research that specifically meets three NIDA key goals: identifying the behavioral and social causes of drug use and addiction, developing new and improved interventions to prevent drug use and its consequences, and assessing the impact of polices on SUD.

PROJECT NARRATIVE Transgender people are at increased risk for substance use disorders (SUD), yet it is unknown how transgender people enrolled in the single largest payer of behavioral health (Medicaid) access screening and treatment for substance use disorders. Identifying factors that facilitate screening and treatment – including access to gender-affirming care (e.g. hormones, surgeries) – is critical to reducing SUD in this population. This proposed mixed methods research identifies predictors of SUD and treatment using claims data from Oregon’s Medicaid program, and interviews with transgender people and clinicians provide context for these findings.