Primary care and physician extenders in affluent countries.

The worldwide growth of specialization in medicine has led to a perceived shortage of primary care. A major response in the United States has been the training of physician extenders (both physician assistants and nurse practitioners). Other industrialized countries have rejected this approach, in favor of strengthening general medical practice through continuing education, provision of ancillary personnel, use of health centers, and by other methods. Developing countries use doctor-substitutes as a reasonable adjustment to their lack of economic resources. All countries use ancillary personnel for selected procedures, such as midwifery, which involve only limited judgment and decision making. The American strategy on use of doctor-substitutes for primary care, however, follows from unwillingness to train greater numbers of primary care physicians and to require them to serve in places of need. This results in an inequitable concentration of doctor-substitutes on service to the poor in both urban and rural areas.