Guideline-recommended medications: variation across Medicare Advantage plans and associated mortality

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.

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.

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).

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.