Dr. Starr raises legitimate concerns regarding the impact of hospitalists on internal medicine, notwithstanding our finding that 89% of hospitalists are internists (1). He may be relieved to learn that the earliest hospitalist groups were developed by physicians; insurance companies are only recent converts. Moreover, most hospitalist programs are voluntary; the independent choice of physicians like Dr. Starr is fueling the movement. He will be heartened by the vigorous stance that the American College of Physicians-American Society of Internal Medicine and the National Association of Inpatient Physicians have taken against the mandatory use of hospitalists by insurance companies (2). Finally, perhaps he will recognize that average internists now spend more than 85% percent of their time caring for ambulatory patients, even when there are no hospitalists. Internists can no longer depend on their hospital work for education or for demonstrating their competitive edge over other providers.

I applaud Dr. Hoffman's skepticism. The data on the value of hospitalists are positive (3-5), but more research is needed. Although I too worry about burnout, our survey of nearly 400 hospitalists showed that 94% were satisfied and few anticipated returning to primarily ambulatory practices (1). A generation ago, internists who focused on emergency or critical care medicine were probably counseled not to lose their ambulatory skills so as to keep their options open in case their new "specialties" evaporated. Few such physicians were forced to return to outpatient practice, and I suspect the same will be true for hospitalists.

Dr. Rastegar is right to question the 25% threshold for inpatient care in my hospitalist definition. In fact, about two thirds of the hospitalists we surveyed were fully hospital-based (1). However, a definition of 100% or even 50% inpatient time would exclude most academic hospitalists. At my institution, hospitalists serve in the inpatient role for 3 to 6 months per year; this seems to generate the experience, expertise, and investment in the inpatient service needed to meet the spirit of the definition. We also benefit from the participation of a group of nonhospitalists on our medical service, although they continue to be somewhat less efficient than hospitalists (3; Auerbach A. Unpublished data). Our hospitalists generally maintain a small outpatient presence, which may help prevent burnout and improve their sensitivity to ambulatory issues. Research is needed to determine whether this outpatient time is sustainable and to define the "optimal" amount of inpatient practice time for hospitalists.

The experiences of Wald and Flansbaum and colleagues reflect my own and those I've observed at dozens of academic and community hospitals. In these programs, once the turf battles are put aside, reasonable job descriptions constructed, communication links forged, and sustainable support obtained, patients and trainees benefit from the presence of hospitalists who can hone their acute care skills, remain available to hospitalized patients throughout the day, and make continuous improvement in the inpatient environment part of their daily agenda. Moreover, academic hospitalists are forging exciting educational pathways and undertaking research to answer important questions about the hospital and its interfaces. The value of these efforts, combined with data on the costs and quality of hospitalist versus nonhospitalist care, will determine the viability of this new field.