The effects of institutional change on geographic variation and health services use in the USA

▸ Develops and tests hypotheses predicting impacts of institutional change in American health care on patient care. ▸ Identifies institutional change and diffusion of cost-effective patient care practices as causes of geographic variation in medical care. ▸ Shows that clinical guidelines and managed care organizations can reduce health services use, diffuse new patient care practices, and standardize patient care. ▸ Emphasizes importance of using longitudinal data to analyze geographic variation.