Risk-adjusted mortality as an indicator of outcomes: comparison of the Medicare Advantage Program with the Veterans' Health Administration

Abstract

Background: The Medicare Advantage Program (MAP) and the Veterans' Health Administration (VHA) currently provide many services that benefit the elderly, and a comparative study of their risk-adjusted mortality rates has the potential to provide important information regarding these 2 systems of care.

Objective: The objective of this retrospective study was to compare mortality rates between the MAP and the VHA after controlling for case-mix differences.

Subjects: This study consisted of 584,294 MAP patients and 420,514 VHA patients.

Measures: We used the Death Master File to ascertain the vital status of each study subject over approximately 4 years. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the MAP compared with VHA patients.

Results: The average age for male MAP patients was 73.8 years (+/- 5.6) and for male VHA patients was 74.05 years (+/- 6.3). Unadjusted mortality rates of males for VHA and MAP were 25.7% and 22.8%, respectively, over approximately 4 years (P < 0.0001), respectively. The case-mix of VHA patients, however, was sicker than those from MAP. After adjusting for case-mix, the HR for mortality in the MAP was significantly higher than that in the VHA (HR, 1.404; 95% CI = 1.383-1.426). We obtained similar results when we compared the mortality rates of females for VHA and MAP.

Conclusions: After adjusting for their higher prevalence of chronic disease and worse self-reported health, mortality rates were lower for patients cared for in the VHA compared with those in the MAP. Further studies should examine what differences in care structures and processes contribute to lower mortality in the VHA.