The structure of the practice of clinical medicine has changed profoundly in the past 20 years or more, and the changes are accelerating almost by the month. The use of the word "structure" is intended to denote and include the organization of the provision of care, the methods of payment for health care, and, more important, the relationships between patient and physician, patient and payer, and physician and payer. The changes, for the most part, have occurred because health costs have been increasing at a rate viewed as unacceptable to the public. Despite the increased expenditures, sizable portions of the public have limited access to health care.
The structure of clinical research also has changed substantially in the same period, although for somewhat different reasons. Pharmaceutical manufacturers and new biotechnology firms have developed many new therapeutic products that require human testing before approval. At the same time, colleges of medicine,