The evolution of the hospitalist model in the United States

In the 1990s, a competitive market for health care emerged in the United States, one in which patients and purchasers began to seek out less expensive (and high-quality) care delivery systems. These pressures to more efficiently use hospital resources, coupled with new technologies and organizational innovations that displaced a significant amount of hospital care to ambulatory and short-stay environments, prompted a rethinking of the organization of inpatient care in the United States. In 1996, Wachter and Goldman [1] described a model of care in the United States, in which a new group of physicians-termed hospitalists provide inpatient care in place of primary care physicians or 1 month per year attendings in academic medical centers. The authors cited several forces promoting this change, including the cost pressures and increased acuity in hospital care, the time pressures on primary care physicians in the office, the shrinking inpatient volumes of most primary physicians, and the evidence that practice seems to "make perfect" in other medical fields. The authors predicted that the hospitalist movement would grow, and ultimately become a, if not the, dominant model for inpatient care in the United States. Finally, the authors argued that judgments regarding the hospitalist model should be informed by data on cost, quality, education, and patient satisfaction. Movement toward the hospitalist model comes in the midst of a debate regarding the relative merits of specialty versus generalist care. Advocates of the latter cite the merits of comprehensiveness and continuity. Recent literature, however, has confirmed volume-to-outcome relationship in the care of patients with organ- or system-specific problems such as acute myocardial infarction [2], with complex diseases such as AIDS, [3] and in the performance of procedures such as percutaneous transluminal coronary angioplasty [4] and esophageal surgery [5]. Although the notion of a site-defined (rather than a population-, organ-, or disease-defined) specialty seems novel, it is not; medicine in the United States embraced the "generalist specialist" when it accepted the specialties of emergency medicine and critical care medicine a generation earlier (Table 1). What is new, at least in the United States, is the approach of using a site-defined specialist on the main hospital ward. Despite the long tradition of separate providers of hospital care in most other industrialized countries such as the United Kingdom and Canada [6,7], the displacement of the primary care physician from hospital care in the United States has caused considerable controversy. The strong reactions to the Wachter and Goldman study [1] illustrated that this new model for hospital care has both potential advantages and disadvantages in comparison with more traditional models [8-11]. This article reviews the forces that have led to this major change in the organization of US hospital care, the data on the impact of hospitalists, and some of the effects that hospitalists are having on the systems in which they work.