Passage of the Patient Protection and Affordable Care Act (ACA) in March 2010 created the Medicare Hospital Readmissions Reduction Program (HRRP), which introduced the prospect of financially penalizing hospitals based on their previous performance. This program represents one of several efforts to encourage provider organizations to enhance safety and value. Medicare has reported lower readmission rates since passage of the law, but whether the lowest-performing hospitals might experience less rapid improvement than hospitals that are already performing well, due to being underresourced or serving vulnerable populations, has been questioned
In the context of this uncertainty, we analyzed time-series data on all-cause and condition-specific 30-day risk-standardized readmission rates (RSRRs) for Medicare fee-for-service enrollees from 2000 to 2013 to answer 2 questions. First, we sought to confirm that hospital RSRRs for AMI, CHF, and pneumonia decreased after passage of the ACA compared with any preexisting trends in improvement before passage of the law. Second, we determined whether the acceleration of improvement in readmission rates after passage of the law was greater in the lowest-performing hospitals than in higher-performing hospitals.