Dr. Landon’s research is focused on understanding the impact of organizational and physician characteristics on the delivery of health care services. Dr. Landon has applied rigorous methodology from the disciplines of clinical epidemiology and health services research to answer critically important questions about the cost and quality of care. In a series of articles spanning the last decade, Dr. Landon studied the impact of managed care programs on quality of care, with a focus on the Medicare and Medicaid programs. He showed that that traditional Medicare Beneficiaries had better care experiences than those enrolled in managed care, but received preventive services at lower rates. He also found that Medicaid managed care enrollees systematically receive care of lower quality when compared to commercial managed care enrollees, even when enrolled in the same health plan. Dr. Landon has also focused on the impact of health care organizations beneath the health plan at the level of practice sites and medical groups. He has led the two largest and most rigorous studies of quality improvement collaboratives, among the most commonly employed organizational interventions to improve quality of care in these settings. Dr. Landon’s work showed that collaboratives led to important improvements in the processes of care for patients with chronic medical conditions. Dr. Landon’s current work involves the study of physician-level financial incentives and pay-for-performance, information sharing among physicians through informal social networks, and the comparative effectiveness and adoption of technological advances, using vascular surgery interventions as a model.