Primary prevention aspirin use among U.S. adults has decreased significantly following updated clinical guidelines; however, many patients who may not benefit continue to take the medication, according to a new study.
Investigators analyzed data from 18,294 participants involved in the 2011 to 2023 National Health and Nutrition Examination Survey (NHANES), finding that primary prevention aspirin use dropped from 23.5% between 2017 and 2020 to 17.2% between 2021 and 2023, representing a decrease of 6.3 percentage points.
"Following landmark clinical trials and changes in guideline recommendations, self-reported primary prevention aspirin use decreased among older adults and adults with low [atherosclerotic cardiovascular disease] (ASCVD) risk for whom aspirin was not recommended but also decreased among adults with higher ASCVD risk for whom aspirin may still be recommended," wrote study authors Linnea M. Wilson, MPH, and Timothy S. Anderson, MD, MAS in JAMA.
The decline was most pronounced among adults over 70 years old, dropping from 46.1% to 34.4%. Adults with low ASCVD risk (< 10%) showed a reduction from 16.5% to 10.8%.
The study found disparities in aspirin use reduction across demographic groups. While aspirin use decreased significantly among White and other Hispanic populations, no statistically significant changes were observed among Asian, Black, or Mexican American populations. Additionally, individuals without a routine health care location, those insured by Medicaid, or those without insurance showed no significant decrease in aspirin use.
Secondary prevention aspirin use among patients with known ASCVD remained stable throughout the study period, with rates of 69.9% between 2011 and 2012 and 66.3% between 2021 and 2023.
The research followed the 2019 American College of Cardiology/American Heart Association guideline on ASCVD primary prevention, which narrowed recommendations for preventive aspirin use to individuals at higher ASCVD risk and 70 years or younger without increased bleeding risk. These changes were further supported by 2022 recommendations from the U.S. Preventive Services Task Force against initiating primary prevention aspirin in patients 60 years and older.
Study limitations included reliance on self-reported aspirin use, the cross-sectional nature of the data, and falling response rates in NHANES surveys. The investigators also noted that bleeding risk beyond advanced age was not assessed, and information about the use of other antiplatelets or anticoagulants was not collected from 2021 to 2023.
The study was funded by the National Institute on Aging and conducted by researchers from Beth Israel Deaconess Medical Center, the University of Pittsburgh, and the VA Pittsburgh Health System.
Full disclosures can be found in the research letter.
