Polypharmacy and health beliefs in older outpatients.

BACKGROUND

Polypharmacy is a significant problem among older adults. Patient-related characteristics and beliefs have not been the focus of prior research in this area, which has primarily evaluated the effects of patients' health status and health care system factors.

OBJECTIVE

The goal of this research was to determine the prevalence and predictors of unnecessary drug use in older veteran outpatients, with a focus on patient-related factors and health beliefs.

METHODS

Community-dwelling veterans aged > or =60 years, with > or =5 self-administered medications per day, not cognitively impaired, able to speak and/or write English, and receiving primary care and medications from a large urban Veterans Affairs Medical Center were eligible for study. Assessment of unnecessary drug use was determined by clinical pharmacists applying the criteria of the Medication Appropriateness Index to each regularly scheduled medication. Those drugs that received an inappropriate rating for indication, effectiveness, or therapeutic duplication were defined as unnecessary. Health beliefs regarding medication use were assessed with decisional balance, self-efficacy, and health locus of control scales.

RESULTS

A total of 128 veterans (mean [SD] age, 72.0 [8.9] years; 93.0% white; 93.0% male) were enrolled. Analysis showed that 58.6% of patients had > or =1 unnecessary prescribed drug; the most common reason for a medication being considered inappropriate was lack of effectiveness (41.4%). The most commonly prescribed unnecessary drug classes were central nervous system (19.5%), gastrointestinal (18.0%), and vitamins (16.4%). Factors with tendency for association (P < 0.20) with any unnecessary drug use included race (white), income (<$30,000/year), number of prescription medications (mean [SD], 6.8 [2.8]), and lack of belief in a "powerful other" for their health locus of control.

CONCLUSIONS

We found a very high prevalence of unnecessary drug use in this older veteran outpatient population. Race, income, and polypharmacy, as well as health-related beliefs, were central factors associated with unnecessary drug use.