A team of researchers from UAB's School of Public Health collaborated to identify hospital/county characteristics and sources of regional heterogeneity associated with readmission penalties. Members of the team included doctoral candidate, Ms. Monica Aswani, along with Drs. Meredith Kilgore, David Becker, and Bisakha Sen all from the Department of Health Care Organization and Policy, Dr. David Redden from the Department of Biostatistics, along with a former colleague, Dr. Justin Blackburn, now with Indiana University Richard M. Fairbanks School of Public Health, Indianapolis, IN.

Acute care hospitals under the Hospital Readmissions Reduction Program from fiscal years 2013 to 2018 were linked to data from the Annual Hospital Association, Centers for Medicare and Medicaid Services, Medicare claims, Hospital Compare, Nursing Home Compare, Area Resource File, Health Inequity Project, and Long term Care Focus. The final sample contained 3,156 hospitals in 1,504 counties.

Data sources were combined using Medicare hospital identifiers or Federal Information Processing Standard codes.

A two level hierarchical model with correlated random effects, also known as the Mundlak correction, was employed with hospitals nested within counties.

The authors concluded that as the readmission risk adjustment does not include any community level characteristics or geographic controls, the resulting endogeneity bias has the potential to disparately penalize certain hospitals.