Use of Administrative Claims Models to Assess 30-Day Mortality Among Veterans Health Administration Hospitals

Abstract

Background: The Centers for Medicare and Medicaid Services (CMS) publicly reports hospital-specific risk-standardized, 30-day, all-cause, mortality rates (RSMRs) for all hospitalizations among fee-for-service Medicare beneficiaries for acute myocardial infarction (AMI), heart failure (HF), and pneumonia at non-Federal hospitals. Objective: To examine the performance of the statistical models used by CMS among veterans at least 65 years of age hospitalized for AMI, HF, and pneumonia in Veterans Health Administration (VHA) hospitals. Research Design: Cross-sectional analysis of VHA administrative claims data between October 1, 2006 and September 30, 2009. Subjects: Thirteen thousand forty-six veterans hospitalized for AMI among 123 VHA hospitals; 26,379 veterans hospitalized for HF among 124 VHA hospitals; and 31,126 veterans hospitalized for pneumonia among 124 VHA hospitals. Measures: Hospital-specific RSMR for AMI, HF, and pneumonia hospitalizations calculated using hierarchical generalized linear models. Results: Median number of AMI hospitalizations per VHA hospital was 87. Average AMI RSMR was 14.3% [95% confidence interval (CI), 13.9%–14.6%] with modest heterogeneity among VHA hospitals (RSMR range: 8.4%–20.3%). The c-statistic for the AMI RSMR statistical model was 0.79. Median number of HF hospitalizations was 188. Average HF RSMR was 10.1% (95% CI, 9.9%–10.4%) with modest heterogeneity (RSMR range: 6.1%–14.9%). The c-statistic for the HF RSMR statistical model was 0.73. Median number of pneumonia hospitalizations was 221.5. Average pneumonia RSMR was 13.0% (95% CI, 12.7%–13.3%) with modest heterogeneity (RSMR range: 9.0%–18.4%). The c-statistic for the pneumonia RSMR statistical model was 0.72. Conclusions: The statistical models used by CMS to estimate RSMRs for AMI, HF, and pneumonia hospitalizations at non-Federal hospitals demonstrate similar discrimination when applied to VHA hospitals.