My overarching research theme focuses on ways to improve the quality of medical care for patients with common medical problems. As Director of the VA CHERP, he is particularly interested in conducting research to detect, understand and eliminate disparities in health and health care among vulnerable patient populations. His past research employed retrospective and prospective cohort designs, with extensive emphasis on assessment of patient-centered outcomes. His current research utilizes randomized clinical trial design to test the effectiveness and safety of medical practice guidelines to improve the quality and efficiency of care for patients with common medical illnesses.