PROJECT SUMMARY/ABSTRACT This GEMSSTAR R03 award will establish Dr. Anil Makam as a clinician-investigator focused on the impact of post-acute care on health outcomes after acute illness in the elderly. This R03 award will provide him the support needed to develop expertise in 3 focused areas: (1) geriatric clinical training in post-acute care; (2) health services research (HSR) using Medicare data; and (3) advanced statistical methods in comparative effectiveness research (CER). To achieve these goals, Dr. Makam has assembled an expert multidisciplinary team in HSR, CER, geriatrics, rehabilitation, and post-acute care. His primary mentor, Dr. Ethan Halm, has extensive experience in HSR, CER and mentoring junior faculty to become independent investigators. His scientific advisors include Dr. Jim Goodwin, a leading expert in using Medicare data for aging research, and Dr. Song Zhang, an expert in advanced biostatics. Dr. Makam will also benefit from the expertise of 2 renowned clinical advisors in geriatrics (Rubin) and post-acute care (Muldoon). The use of post-acute care among the elderly is rising, and accounts for 73% of the geographic variation in Medicare spending. Long-term acute care hospitals (LTACs) are the fastest growing segment of post-acute care. Despite this growth and variation, little is known about why hospitalized older adults are discharged to LTACs versus receiving continued care in the acute care hospital (ACH), and which setting will optimize their recovery. Informed by his clinical experience as a hospitalist and his preliminary data, Dr. Makam will conduct a series of national studies to answer these essential questions. He will use national Medicare data to identify patient, hospital, and regional-level factors associated with LTAC use (vs. ACH) and quantify the degree of variation at each level (Aim 1). To comparatively assess the effectiveness of LTACs versus continued care in an ACH on outcomes, utilization, costs, and spending, Dr. Makam will use propensity score and instrumental variable analyses to control for both measured and unmeasured differences in the selection of which older adults are discharged to a LTAC (Aim 2). This research plan leverages existing institutional resources, including the UTSW CTSA and Dr. Halm?s AHRQ-funded Center for Patient-Centered Outcomes Research, as well as Dr. Goodwin?s NIA-funded geriatric and rehabilitation outcomes research group. Finally, this training and research will complement his K23 proposal comparing LTACs versus skilled nursing facilities, the principal post-acute care alternate. Together, his R03 and K23 proposals will inform a subsequent R01 application to further study the comparative effectiveness of LTACs vs. alternate care options and their associated long-term functional and cognitive outcomes. This proposal and the subsequent research will directly inform practice and policy by building the evidence base to assist patients, providers, and payers to ?choose wisely? in post-acute care.