Physician Networks for Diabetic Lower Extremity Wounds - Summary/Abstract Diabetic lower extremity (DLE) wounds affect up to 34% of adults with diabetes and are associated with substantial clinical morbidity/mortality, increased healthcare utilization, and higher cost of care. However, persistent racial/ethnic and socioeconomic disparities among DLE wounds remain poorly addressed, and little is known about the utilization of physician services and role of physician networks in observed disparities. This proposal responds to PAR-20-310, Health Services Research on Minority Health and Health Disparities, by conducting a national evaluation of racial/ethnic and socioeconomic disparities in healthcare utilization among patients with DLE wounds, and assessing the role that physician networks and referral patterns play in observed disparities. Through the RAND AHRQ U19 Center of Excellence on Health System Performance, our study will leverage several Medicare data sources, unique physician-level preliminary data, and innovative methods to improve beneficiary classification of race/ethnicity. The study will focus on Medicare fee-for-service beneficiaries aged 65 years and older with a new DLE wound and track longitudinal utilization of healthcare services across multiple clinical settings during the 6-month period following initial wound diagnosis. In Aim 1, we will use multivariable regression techniques to evaluate racial/ethnic and socioeconomic disparities in healthcare utilization after initial DLE wound diagnosis. Then, we will map and characterize physician networks and referral patterns for DLE wounds and examine the effects of network/referral pattern characteristics on healthcare utilization disparities (Aim 2). Finally, in Aim 3, we will simulate changes to network/referral pattern characteristics and identify which characteristics have stronger disparity reducing effects, and therefore, are amenable to intervention development. The proposed study will identify potentially modifiable aspects of physician networks and referral patterns that contribute to observed disparities in DLE wound care. Results will inform how policy regarding physician network adequacy, health system organization, and payer incentives can improve quality of care for patients with DLE wounds and reduce disparities in healthcare utilization. The project team consists of multiple NIH funded researchers with ample expertise in health disparities research, network analysis of claims data, statistical methods, and knowledge of clinical context.