Project Summary Stroke is a highly prevalent condition that contributes to significant deficits in functional mobility, particularly in older adults. To address these deficits, post-acute rehabilitation is an evidence-based component of care. However, facility-based rehabilitation (i.e., in a skilled nursing or inpatient rehabilitation facility) is costly. If stroke patients can achieve the same outcomes in a high-intensity home-based rehabilitation (HIHR) approach as in these facilities, the relative value (outcomes/costs) would be greater. The effectiveness of such an approach has not been studied. Further, the implementation of a HIHR care model has not been examined in the US health system. The objectives of the proposed research are to identify barriers to initial HIHR efforts implementation in one health system and to understand its clinical effectiveness to inform subsequent improvement of the care model. A hybrid type 2 study design with a triangulated mixed methods approach will be used over two cycles of a learning health system research framework. Specific aims are to (1) explore barriers affecting the initial implementation of HIHR for stroke patients, (2) compare the effectiveness of HIHR to facility-based rehabilitation on improving patients' function, and (3) implement a refined HIHR model and re- examine its implementation and effectiveness. We hypothesize that clinical workflow challenges and patient/caregiver preferences will affect the outcomes with initial implementation and that patients' function at HIHR discharge will be at least equivalent to patients' function at facility discharge. We also hypothesize that improvements in implementation and effectiveness outcomes will be achieved by refining the HIHR model after learning from the evaluation of the initial model. These aims align well with the candidate's goal to become an independent learning health system researcher, with an emphasis on studying rehabilitation practice in health systems. Training aims are to (1) develop expertise in mixed methods research and its application to care delivery, (2) gain expertise in assessing implementation success of a health system innovation, (3) develop expertise in comparative effectiveness research using observational data, and (4) develop skills to engage with health system leaders and lead a learning health system research lab. These training aims will be accomplished via one-on-one mentorship with content experts and combination of local and national coursework. All scientific and training aims will be accomplished in an environment that includes a large integrated academic health system and a partner institution for didactic instruction. The expected outcome of this work is a description of the implementation and effectiveness outcomes for HIHR. This is an innovative approach for post-acute rehabilitation following stroke that does not currently exist in the US health system, but which may substantially affect the value of care ...