Role of Health Care in Addressing Unhealthy Alcohol Use and Disparities among Aging Women - Unhealthy alcohol use has increased significantly among aging women, raising their risk of serious alcohol related adverse consequences. At the same time, they face significant challenges accessing treatment. As the population of the United States ages, health care providers and systems will face an increasing number of aging women with alcohol problems, often with co-occurring health conditions that would improve with reduced drinking. Currently, there is limited research on the growing needs of this aging population, including on how some subgroups may be impacted by unhealthy alcohol use and on how to develop effective interventions so that the whole population can experience improved outcomes. To understand these critical gaps and inform a holistic approach to alcohol-related healthcare, we propose a mixed-method study of over one million (1,298,009) aging women (≥age 50) in a large health care delivery system of over 4.5 million members. We leverage unique longitudinal electronic health record (EHR) data from a universal alcohol screening program in primary care, with an estimated 784,794 aging women regularly screened for unhealthy alcohol use at multiple primary care visits between 2014-2022. We integrate screening data with a NIAAA-funded alcohol registry that contains medical and psychiatric diagnoses, self-report health behaviors (e.g. tobacco, exercise, interpersonal violence screening), and health service encounters across clinical settings. Our approach is guided by a conceptual model based on the Andersen Model of Health Services Utilization. We first identify trends and predictors of unhealthy alcohol use (defined as exceeding guidelines or alcohol use disorder) among aging women. Second, we test whether health services utilization (e.g., routine primary care visits, brief alcohol interventions, medications, and addiction and/or psychiatry treatment) is associated with reductions in alcohol use over time among all aging women who report unhealthy alcohol use and among subsets with co-occurring health conditions (e.g., chronic pain, depression/anxiety, diabetes and hypertension) and medication use (e.g., opioids). We use advanced causal modeling approaches to analyze hypothesized relationships, and to appropriately control for potential confounding and biases. For a deeper understanding of these patients’ needs and potential challenges to seeking care, we will conduct qualitative interviews with aging women who report unhealthy alcohol use and with providers who care for them in different medical settings (e.g. primary care, geriatrics, addiction medicine), which we triangulate with the quantitative data. Findings will provide urgently needed evidence on how health services can impact unhealthy alcohol use, so that health care systems can better identify and treat this population through targeted interventions.