The potential size of the hospitalist workforce in the United States

In the United States, there are currently 1,000 to 2,000 physicians who specialize in inpatient hospital care. The number of such hospitatists appears to be growing rapidly, but the ultimate size of the hospitalist workforce is not known.

We obtained workload data from 365 practicing hospitalists who completed a survey by the National Association of Inpatient Physicians. We then estimated the number of potential hospitalists, based on published national hospital census data. We assumed that hospitalists would care for all medical inpatients, but only at hospitals large enough to require > or = 3 hospitalists. We also made estimates based on the primary care physician referral base and international benchmarks. We estimated hospitalists' primary care referral base from telephone interviews with key informants. Official sources in England and Germany provided international workforce data.

Hospitalists reported an average workload of 13 inpatients. To cover all adult medical inpatients in the United States, we estimate a potential workforce of 19,000 hospitalists. Sensitivity analysis yielded 10,000 to 30,000 hospitalists. Our alternative models yielded estimates within this same range.

The future hospitalist workforce is potentially quite large. This finding highlights the need to evaluate the economic and clinical outcomes of hospitalist systems.