Dr. Landon’s primary research interest has been assessing the impact of different characteristics of physicians and health care organizations, ranging from health plans to physician group practices on physician behavior and the provision of health care services. His work in this area has included the development of a theoretical model to explain how health care organizations affect the quality of care, and he is now involved in several projects that will help describe and quantify the impact of a variety of organizational characteristics and strategies, including quality improvement strategies and financial incentives, on the provision of care. Dr. Landon currently serves as the principal investigator of an RO1 from the National Institutes of Aging studying the influence of informal physician social networks on local practice patterns and the diffusion of new technologies. Dr. Landon also is a project leader on an NIA-funded program-project grant that seeks to examine quality of care and utilization patterns in the Medicare Advantage program.