Predictors of high-risk prescribing among elderly Medicare Advantage beneficiaries

To examine patient, community, and insurance plan predictors of high-risk prescribing in the elderly Medicare Advantage population.

Cohort study.

Using a sample of 203 Medicare Advantage plans from the 2006-2008 Health Outcomes Survey, we compared patient, community, and insurance plan characteristics of 77,247 respondents with and without new Medicare Part D claims for high-risk medications from June 2006 to May 2007.

Of the Medicare Advantage enrollee respondents, 15.6% received a new prescription for a high-risk medication during 12 months of follow-up. In adjusted analyses, new users of high-risk medications were more likely to be women (OR = 1.35; 95% CI,1.28-1.42), and they reported poorer general health (Physical Component Summary score 37.3 vs 40.4, P <.05) than did individuals who never received a high-risk prescription. Being aged ≥ 85 years was protective against receipt of a high-risk medication (OR relative to persons aged 65-69 years = 0.69; 95% CI, 0.64-0.75). Incidence of high-risk prescribing varied by census division, with a 2-fold difference between regions with the lowest and highest rates (9% in New England vs 18% in the West South Central region). Muscle relaxants, antihistamines, and opiates accounted for over 71% of new dispensing of high-risk medications. Approximately 67% of new users of high-risk medications received only 1 dispensing.

High-risk prescribing varies widely by geography and drug class in the Medicare Advantage population. Women, persons with poorer self-reported health, and those residing in the Southern regions of the United States more frequently receive high-risk medications. Variations may highlight areas for targeted interventions to reduce high-risk prescribing to the elderly.