Trends in adult visits to primary care physicians in the United States

Background: Although numerous changes are apparent in the US health care sy stem, little is known about how these changes have altered the work of prim ary care physicians. Methods: We analyzed a nationally representative sample of 136 233 adult of fice visits to general internists, general practitioners, and family physic ians contained in the 1978 through 1981, 1985, and 1989 through 1994 Nation al Ambulatory Medical Care Surveys. Annual sample sites varied between 5662 and 19 977 visits. Measures included the characteristics of patients prese nting to primary care physicians, physician activities during these visits, and the disposition of the visits to primary care physicians. Results: Visits to primary care physicians have diminished as a proportion of all adult visits from 52% in 1978 to 41% in 1994. Dramatic trends in adu lt primary care included the growing racial or ethnic diversity of patients , the doubling (since 1985) of health maintenance organization coverage, in creased provision of prevention services, changes in the most common medica tions, and an 18% increase in the duration of adult visits to primary care physicians. Conclusions: Trends in primary care practice reflect changes in society and in the US health care system, including demographic changes, an emphasis o n prevention, and the growth of managed care. The increasing role of manage d care, with its emphasis on increased productivity, appears at odds with p rimary care physicians' increasing responsibility for prevention and the as sociated increase in the duration of primary cart visits.