Wrestling with variation: an interview with Jack Wennberg [interviewed by Fitzhugh Mullan].

For thirty years Jack Wennberg has studied variations in medical practice, from rates of tonsillectomy in Vermont villages in the 1970s to the cost of dying in the nation's major medical centers today. Along the way he has spawned the field of clinical evaluative science, created the Dartmouth Atlas of Health Care, stimulated the creation of a new federal agency (the Agency for Healthcare Research and Quality), and challenged many presumptions about what constitutes good medical care. In this interview with Fitzhugh Mullan, he reflects on health care reform and how to change clinical practice.