Hospitalists and Hospital Productivity

Over the past decade there has been a steady rise in the use of hospitalists to manage inpatient care at U.S. hospitals. The percentage of hospitals in which hospitalists provide care increased from less than 20% in 2003 to more than 40% in 2010. Hospitalists are physicians who work exclusively in an inpatient setting, focusing on the general medical care of hospitalized patients.  The hospitalist model of care has supplanted the traditional model in which primary care physicians do rounds at the hospital to attend to their hospitalized patients.     

Hospitalists are familiar with the hospital environment and are better able to coordinate care, implement process improvements and respond quickly to patient needs. However, they result in discontinuity of care as the primary responsibility for patients is transferred from the primary care physician to the hospitalist upon the admission of a patient to the hospital.  Thus, hospitalists could help to curb resource use at hospitals while having an ambiguous effect on quality. Using data from the American Hospital Association (AHA) and the AHRQ's Nationwide Inpatient Sample (NIS) database, we investigate whether hospitals that employ hospitalists achieve reductions in risk-adjusted length of stay over the time period 2003 to 2010.

We risk-adjust length of stay using the patient’s age, sex, neighborhood income quartile, and diagnosis-related group (DRG). Additionally, we categorize each discharge as either medical or surgical. We implement patient-level regression models to test the association between hospitalist use and risk-adjusted length of stay, adding hospital fixed effects to control for any time-invariant hospital characteristics.

We find that hospitalist use is associated with an average reduction of 0.059 days in length of stay. For patients whose primary diagnosis is a medical DRG, the average reduction in length of stay is 0.07 days. Both these effects are statistically significant at the 5% level. However, there is no statistically significant impact for surgical patients who are not typically looked after by hospitalists.

We also find that the effect is stronger for complex patients with a high number of comorbidities who require closer attention and more careful coordination.  For medical patients who have more than 2 comorbidities, hospitalist use is associated with a reduction in length of stay of 0.195 days, significant at the 0.1% level. There are no statistically significant effects for surgical patients with a high number of comorbidities.

We continue to find effects with similar magnitudes when we restrict our sample of patients to those with conditions--such as pneumonia, asthma, and urinary tract infections--that are most commonly encountered by hospitalists according to the medical literature. We also find that hospitalist use is associated with small reductions in the mortality rate for high mortality conditions such as congestive heart failure and chronic obstructive pulmonary disease. As a falsification test, we show that there is no association between hospitalist use and length of stay for pregnancies with normal delivery – a category of patients that hospitalists rarely manage. Our findings warrant further investigation into how hospitalists affect other measures of hospital productivity.