Prescription Medication Use Among Women Aged 40 and Older in the United States from 1999 to 2020.

IMPORTANCE: Prescription medication use in the United States has increased over recent decades, with women consistently reporting higher use than men. However, limited research has examined use patterns among women, particularly those 40 years and older who face elevated risks for chronic disease. OBJECTIVE: To assess prescription medication use among U.S. women 40 years and older. DESIGN/SETTING: Cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) data from 10 survey cycles spanning 1999-2020. PARTICIPANTS: A total of 18,686 women aged 40 years and older with complete prescription medication information. EXPOSURE: Calendar year modeled as NHANES cycles. MAIN OUTCOME(S) AND MEASURE(S): Prescription medication use in the past 30 days, overall and by therapeutic class, was estimated for each NHANES cycle. Joinpoint regression estimated average annual percent change (APC). Logistic regression assessed associations between covariates and medication use and polypharmacy (≥5 medications). RESULTS: Polypharmacy among female participants rose from 17.9% in 1999-2000 to 26.0% in 2017-2020, demonstrating an increasing trend early (1999-2004 APC: 7.4, [95%CI: 1.9, 13.6]) followed by stable use (2004-2020 APC: 0.8 [-2.7, 1.9]). Increases in polypharmacy use occurred across racial and ethnic groups and were greatest among women aged 70-85 years. Cardiovascular (1999-2020 APC: 0.9 [0.4, 1.4]) and metabolic (1999-2006 APC: 7.9 [4.1, 15.8]) agent use increased across survey cycles while hormones/hormone modifier use declined (1999-2008 APC: -6.0 [-14.0, -1.3]). CONCLUSIONS AND RELEVANCE: Polypharmacy use increased among women 40 years and older, with notable shifts across therapeutic classes. These trends highlight the need for continued surveillance of medication patterns within this population.