Trends in polypharmacy among U.S. adults with asthma, 2001-2020.

Objective: This study aimed to evaluate trends in polypharmacy prevalence among adults with asthma in the United States.

Methods: Data from the 2001-2020 National Health and Nutrition Examination Survey were used to estimate the weighted prevalence of polypharmacy. Joinpoint regression analysis was conducted to evaluate trends in polypharmacy. Trends were first evaluated overall and then stratified by asthma severity and asthma control. A multivariable logistic regression model was used to identify factors associated with polypharmacy.

Results: From 2001 to 2020, a stable trend in polypharmacy among U.S. adults with asthma was observed (average annual percent change [AAPC]=1.02, p=0.71). Trends across different asthma severity were stable (mild asthma: AAPC=2.93, p=0.20; moderate asthma: AAPC=-2.22, p=0.35; severe asthma: AAPC=0.45, p=0.82). Trends in adults with good asthma control and those with poor control stayed constant (good control: AAPC=0.82, p=0.68; poor control: AAPC=-1.22, p=0.82). Several factors, including older age, females, Non-Hispanic Black, health insurance coverage, family income, number of healthcare visits, former smokers, multi-morbidities, asthma severity, and asthma control, were associated with polypharmacy.

Conclusions: Polypharmacy prevalence has remained constant among U.S. adults with asthma over the past two decades. Despite a stable overall trend, disparities in polypharmacy prevalence persist across different asthma severity and control status, underscoring the need for tailored medication management to improve asthma care.