Health Outcomes Associated with Polypharmacy in Community-Dwelling Older Adults: A Systematic Review

ObjectivesTo summarize evidence regarding the health outcomes associated with polypharmacy, defined as number of prescribed medications, in older community-dwelling persons. DesignSystematic review of MEDLINE (OvidSP 1946 to May, Week 3, 2014). SettingCommunity. ParticipantsObservational studies examining health outcomes according to number of prescription medications taken. MeasurementsAssociation between number of medications and health outcomes. Because of the importance of comorbidity as a potential confounder of the relationship between polypharmacy and health outcomes, articles were assessed regarding the quality of their adjustment for confounding. ResultsOf the 50 studies identified, the majority that were rated good in terms of their adjustment for comorbidity demonstrated relationships between polypharmacy and a range of outcomes, including falls, fall outcomes, fall risk factors, adverse drug events, hospitalization, mortality, and measures of function and cognition. However, a number of these studies failed to demonstrate associations, as did a substantial proportion of studies rated fair or poor. ConclusionData are mixed regarding the relationship between polypharmacy, considered in terms of number of medications, and adverse outcomes in community-dwelling older persons. Because of the challenge of confounding, randomized controlled trials of medication discontinuation may provide more-definitive evidence regarding this relationship than observational studies can provide.