The relationship between 19-year trends in medication use and changes in physical function among women in the mid-life: A Study of Women's Health Across the Nation pharmacoepidemiology study

Purpose: Medication side effects are a major concern in aging adults who report using an increasing number of medications. The relationship between accumulating medication use and physical function has not been examined in a longitudinal cohort. Methods: We conducted a longitudinal cohort study using prospectively collected data from the Study of Women's Health Across the Nation (SWAN). Community-dwelling women from five US cities were followed for up to 20 years. The exposure of interest was the number of prescription medications. They were examined as a count variable and then for specific categories of medication. The outcome of interest was physical function measured repeatedly using the short form (SF)-36 physical function (PF) scale. Linear mixed models, using repeated measures of sociodemographics and comorbidities were assessed. Results: 1452 participants qualified for the analyses with a median follow-up of 19.2 years. At baseline, the mean age was 46.5 years and 53.5% reported White race. Fully adjusted models demonstrated a reduction in the SF-36 PF of 0.99 for each additional prescription medication used or a 6.14-point reduction for women reporting more than five medications and an 8.92-point reduction among those reporting more than 10 medications. These results were similar across race and ethnicity. Specific medication categories with a significant and largely negative impact (at least a two-point reduction) on physical component score included beta-blockers, analgesics, glucocorticoids, anticonvulsants, anxiolytics, anticoagulants, and anti-depressants. Conclusions: There is a moderate association between increasing medication use and decreasing physical function among women transitioning through the mid-life.