Understanding factors associated with readmission disparities among Delta region, Delta state, and other hospitals.

Objectives: To understand the factors that potentially account for differences in 30-day readmission ratios for pneumonia, heart failure, and acute myocardial infarction (AMI) among hospitals in the Mississippi Delta region (Delta region), in Delta states excluding the hospitals in the Delta region (Delta state), and in the rest of the nation (other).

Study Design: A longitudinal study design from 2013 to 2016.

Methods: The dependent variables were 30-day readmission ratios for AMI, heart failure, and pneumonia. The key independent variables were 2 hospital categories (Delta region and Delta state), year dummies for 2014-2016, and the interactions among hospital categories and year dummies. We conducted 2 analyses for each study condition by estimating models with and without controls for hospital and community characteristics.

Results: The coefficients for the interactions among year dummies and Delta region and Delta state hospitals were negative, indicating that Delta region and Delta state hospitals had higher reductions in readmissions than did other hospitals. After controlling for hospital and community characteristics, the disparities in readmissions for pneumonia and AMI in 2013 between Delta region and other hospitals were weakened (P >.05). Major teaching hospitals and percentage of black population were positively associated with readmissions for all study conditions (P values ranged from <.05 to <.001).

Conclusions: Disparities in 30-day readmissions for the study conditions among Delta region, Delta state, and other hospitals were reduced under the Hospital Readmissions Reduction Program (HRRP). However, community factors that are not currently used for adjustment in HRRP were associated with readmission ratios. Revisions of HRRP should consider including community characteristics in risk adjustment models.