Long-term Cognitive and Functional Effects of Potentially Inappropriate Medications in Older Women

Background: The use of potentially inappropriate medications in older adults can lead to known adverse drug events, but long-term effects are less clear. We therefore conducted a prospective cohort study of older women to determine whether PIM use is associated with risk of functional impairment or low cognitive performance.

Methods: We followed up 1,429 community-dwelling women (≥ 75 years) for a period of 5 years at four clinical sites in the United States. The primary predictor at baseline was PIM use based on 2003 Beers Criteria. We also assessed anticholinergic load using the Anticholinergic Cognitive Burden scale. Outcomes included scores on a battery of six cognitive tests at follow-up and having one or more incident impairments in instrumental activities of daily living. Regression models were adjusted for baseline age, race, education, smoking, physical activity, a modified Charlson Comorbidity Index, and cognitive score.

Results: The mean ± SD age of women at baseline was 83.2 ± 3.3. In multivariate models, baseline PIM use and higher ACB scores were significantly associated with poorer performance in category fluency (PIM: p = .01; ACB: p = .02) and immediate (PIM: p = .04; ACB: p = .03) and delayed recall (PIM: p = .04). Both PIM use (odds ratio [OR]: 1.36 [1.05-1.75]) and higher ACB scores (OR: 1.11 [1.04-1.19]) were also strongly associated with incident functional impairment.

Conclusions: The results provide suggestive evidence that PIM use and increased anticholinergic load may be associated with risk of functional impairment and low cognitive performance. More cautious selection of medications in older adults may reduce these potential risks.