Evaluation of Risk-Adjusted Home Time After Acute Myocardial Infarction as a Novel Hospital-Level Performance Metric for Medicare Beneficiaries

Background: The utility of 30-day risk-standardized readmission rate (RSRR) as a hospital performance metric has been a matter of debate. Home time is a patient-centered outcome measure that accounts for rehospitalization, mortality, and postdischarge care. We aim to characterize risk-adjusted 30-day home time in patients with acute myocardial infarction (AMI) as a hospital-level performance metric and to evaluate associations with 30-day RSRR, 30-day risk-standardized mortality rate (RSMR), and 1-year RSMR. Methods: The study included 984 612 patients with AMI hospitalization across 2379 hospitals between 2009 and 2015 derived from 100% Medicare claims data. Home time was defined as the number of days alive and spent outside of a hospital, skilled nursing facility, or intermediate-/long-term acute care facility 30 days after discharge. Correlations between hospital-level risk-adjusted 30-day home time and 30-day RSRR, 30-day RSMR, and 1-year RSMR were estimated with the Pearson correlation. Reclassification in hospital performance using 30-day home time versus 30-day RSRR and 30-day RSMR was also evaluated. Results: Median hospital-level risk-adjusted 30-day home time was 24.0 days (range, 15.3-29.0 days). Hospitals with higher home time were more commonly academic centers, had available cardiac surgery and rehabilitation services, and had higher AMI volume and percutaneous coronary intervention use during the AMI hospitalization. Of the mean 30-day home time days lost, 58% were to intermediate-/long-term care or skilled nursing facility stays (4.7 days), 30% to death (2.5 days), and 12% to readmission (1.0 days). Hospital-level risk-adjusted 30-day home time was inversely correlated with 30-day RSMR (r=-0.22, P<0.0001) and 30-day RSRR (r=-0.25, P<0.0001). Patients admitted to hospitals with higher risk-adjusted 30-day home time had lower 30-day readmission (quartile 1 versus 4, 21% versus 17%), 30-day mortality rate (5% versus 3%), and 1-year mortality rate (18% versus 12%). Furthermore, 30-day home time reclassified hospital performance status in ≈30% of hospitals versus 30-day RSRR and 30-day RSMR. Conclusions: Thirty-day home time for patients with AMI can be assessed as a hospital-level performance metric with the use of Medicare claims data. It varies across hospitals, is associated with postdischarge readmission and mortality outcomes, and meaningfully reclassifies hospital performance compared with the 30-day RSRR and 30-day RSMR metrics.