Today's teaching hospitals: old stereotypes and new realities.

Two decades ago teaching hospitals were a relatively small number of large, urban facilities. They were located near medical schools; were recipients of substantial support from local government appropriations and philanthropic donations; were providers of a large volume of ambulatory care to the indigent population; and were the centers for advancing medical research and technology. Since 1960, changes in medical education and the socioeconomic environment have resulted in a dramatic increase in the number and types of hospitals that formally participate in medical education. The traditional characterization of teaching hospitals still applies to some institutions, but hospitals newly affiliated with medical schools have very diverse characteristics. Unfortunately, third parties, regulators, and hospitals often attach the term "teaching hospital" to all of these hospitals as if they were a homogeneous set of institutions. Additional discussion and documentation of similarities and differences among teaching hospitals could benefit both hospitals and regulators when health policies are being formulated.