Trends in High-Severity Billing of Hospitalized Medicare Beneficiaries Treated by Hospitalists vs Nonhospitalists

Abstract

Importance: As US hospital expenditures continue to rise, understanding drivers of high-severity billing for hospitalized patients among inpatient physicians is critically important. Objective: To evaluate high-severity billing trends of Medicare beneficiaries treated by hospitalists vs nonhospitalists. Design, Setting, and Participants: This cohort study used Medicare fee-for-service claims of hospitalized patients from 2009 through 2018 to compare the proportion of high-severity billing between general medicine physicians classified as hospitalists vs nonhospitalists across initial, subsequent, and discharge hospital encounters. We compared physicians within the same hospital using hospital fixed effects and adjusted for patient demographics and comorbidities. Changes in the billing practices were assessed by investigating differences in slopes using an interaction term between physician type and time. Analyses were conducted between August 2021 and January 2022. Exposures: Treatment by hospitalists vs nonhospitalists. Main Outcomes and Measures: High-severity billing for initial, subsequent, and discharge hospital encounters. Results: The sample included 3121260 and 1855678 Medicare beneficiaries treated by hospitalists vs nonhospitalists, respectively. In each year, mean age, proportion female, proportion Black and Hispanic dual status, and mean number of chronic conditions were similar among those treated by hospitalists vs nonhospitalists (standardized mean difference