Background: Polypharmacy has been extensively studied internationally and reported to be increasing among the elderly. Within the United States, few studies have examined polypharmacy trends in the elderly population and even fewer studies addressed those at-risk for polypharmacy.
Objectives: To examine the trends in office-based visits in the United States by the elderly involving polypharmacy and identify elderly at-risk for polypharmacy.
Methods: Data from the 1990 and 2000 National Ambulatory Medical Care Surveys were used to examine polypharmacy visit trends in the elderly. The Bonferroni inequality method was used to analyze the visit estimates and visit rates. Logistic regression analysis was used to model predisposing, enabling, and need factors associated with polypharmacy visits in the elderly using the 2000 survey data.
Results: Office visits involving polypharmacy for elderly patients were estimated to have nearly quadrupled from 10.1 million in 1990 to 37.5 million in 2000. The proportion of visits by elderly patients involving polypharmacy was 7% in 1990 and 19% in 2000. The increase was consistent among all demographic groups and remained significant even after controlling for elderly population increase. Medication classes involved in polypharmacy remained consistent during the study period and included cardiovascular, hormonal, pain, and gastrointestinal medications. Analysis of the 2000 survey data revealed that several need (multiple diagnoses, chronic problems, and specific disease states), predisposing (female gender), and enabling factors (primary care provider visit and health insurance coverage) were associated with polypharmacy visits in the elderly.
Conclusions: The study found a significant increase in elderly patients' office visits involving polypharmacy in the United States. The study also found that several need, predisposing, and enabling factors were associated with polypharmacy visits in the elderly. These findings suggest opportunities to review and manage elderly patients' medications as recommended by Healthy People 2010, a national agenda to improve the health of Americans.