Population cessation of aspirin use for the prevention of cardiovascular disease.

Importance: Aspirin use for primary prevention of cardiovascular diseases (CVD) is widespread with over a third of the adult population using despite guidelines recommending against. Objective: This population-based research documents rates of use and reasons for cessation from 2015 to 2020, a period when guidelines changed. Design: Three cross-sectional telephone surveys were conducted during 2015, 2017, and 2019-20. Setting: A population-based survey in the states of Iowa, Minnesota, North Dakota, South Dakota, and Wisconsin. Participants: The surveys included non-institutionalized resident adults ages 55-79 for women and 45-79 for men with landline telephones. Main Outcomes and Measures: The analysis included 8,197 participants, 4,161 women and 4,036 men after excluding those with a history of cardiovascular disease (secondary prevention). Aspirin use for primary prevention was stable for the first two survey years (39 % in 2015 and 41 % in 2017) but fell significantly to 34 % in the final survey (2019-2020). The most common reason for cessation was "doctor's advice" (38 % of quitters) followed by "heard negative news" with a significant increase from 2015 to 2020 (4 % to 29 % of quitters). Conclusions and Relevance: Despite recent research findings and new guidelines, aspirin is still widely used for primary prevention of CVD in the general population. A combination of slow diffusion and implementation of guidelines, self-medication, and wide availability of low-cost aspirin underlies these trends. Physician advice is effective but more is needed. The influence of the popular media is also substantial. Appropriate implementation of aspirin guidelines requires additional clinician effort. Trial Registration: Clinicaltrials.gov registered on December 1, 2014, NCT02607917.