Apples to Oranges: Should Safety-Net Hospitals Be Compared Only with Each Other?

​Safety-net hospitals have shown improvement in readmission rates, but the Centers for Medicare and Medicaid Services (CMS) still penalizes them unfairly, according to a study published in the September 2016 issue of Health Affairs. The authors analyzed 30-day readmission rates for heart attack, heart failure, and pneumonia from 2013 through 2016 from Medicare's Hospital Compare website and adjusted the figures to include only hospitals subject to CMS penalties. The authors compared risk-adjusted readmission rates for safety-net hospitals with all other hospitals subject to Medicare's Hospital Readmissions Reduction Program (HRRP) and found that, as expected, safety-net hospitals had significantly higher rates of readmission. They defined safety-net hospitals as the "the highest quartile of hospitals according to their percentage of patients eligible for Supplemental Security Income." The differences in readmission rates between safety-net and other hospitals declined over the three years of HRRP. The gap between readmission rates for heart attack, for example, declined from 0.621% to 0.427%. Additionally, improvements in unadjusted readmission rate were greater at safety-net hospitals than at other hospitals.