Guideline-Recommended Medications: Variation Across Medicare Advantage Plans and Associated Mortality

OBJECTIVES: To evaluate variation in the prescription of guideline-recommended medications across Medicare Advantage (MA) plans and to determine whether such variation is associated with increased mortality. METHODS: Observational study of 111,667 patients aged 65 years or older receiving care in 203 MA plans. We linked data from the Medicare Health Outcomes (HOS) Survey cohort 9 (April 2006-May 2008) with the Medicare Part D prescription benefit files (January 1, 2006-December 31, 2007) to examine variation in treatment across MA plans and its association with differences in observed (O)/expected (E) mortality ratio for 5 high-volume chronic conditions: diabetes, coronary artery disease (CAD), congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD)/asthma, and depression. RESULTS: Analysis of variance confirmed that the 203 MA plans differed significantly in their use of guideline-recommended treatment (P≤0.02). Those MA plans with higher use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (r=-0.40; P<0.0001) and beta-blockers (r=-0.27; P<0.0001) in patients with CHF were significantly associated with lower O/E mortality ratios. Those MA plans with higher use of multiple guideline-recommended medications were significantly associated with lower O/E mortality ratios in CHF (r=-0.45; P<0.0001) and diabetes (r=-0.14; P<0.042). There were no significant associations between the variation in performance indicators and mortality ratios in patients with CAD and COPD/asthma. Those MA plans with higher use of antidepressant medications had significantly higher O/E mortality ratios (r=0.28, P<0.0001). CONCLUSIONS: There was wide variation across MA plans in the prescription of guideline-recommended medications that had a measurable relationship to the mortality of elderly patients with CHF and diabetes. These findings can serve to both motivate and target quality improvement programs.