Effects of Changing Guidelines on Prescribing Aspirin for Primary Prevention of Cardiovascular Events

Jennifer Hissett, MD, Brittany Folks, MD, Letoynia Coombs, MS, William LeBlanc, PhD, and Wilson D. Pace, MD


J Am Board Fam Med. 2014;27(1):78-86. 

In This Article


Table 1 summarizes the distribution of the 131,050-person cohort by sex, average age, and diagnosis in a hierarchical fashion. The overall subpopulation used in this analysis has slightly more males than females (50.6% vs 49.4%), and the average age of women in each cohort is older than the males, with the exception of the group with peripheral vascular disease.

Table 2 displays the number of individuals with diagnoses of interest (CVD risk equivalency for primary prevention and diagnosed CVD for secondary prevention) by time period and the number of people taking aspirin, and the percentage of each cohort that is taking aspirin. It is further separated by individuals with a diagnosis established before the first day of the period (current) and those individuals who were newly diagnosed during a given time period (new). Given that individuals can be included in more than one primary prevention cohort, the totals per cohort exceed the total population studied. The table demonstrates an increase in the percentage of individuals recorded as using aspirin for primary prevention over time, with the exception of hyperlipidemia and hypertension in 2008. There is no indication of any consistent decrease in aspirin usage over time related to individuals who newly enter the groups with a >10% 10-year Framingham risk score for a future coronary artery event.

Table 3 shows the total number of patients with new or current disease taking aspirin. Figure 1 displays the percentage of the entire study cohort recorded as using aspirin across the various periods by diagnosis. From 2007 to 2011, aspirin usage reflected in the EHR increased for the entire cohort and for each individual diagnosis. Aspirin usage for secondary prevention is displayed in Figure 2. Among those with a new diagnosis of CVD, aspirin usage has steadily increased over the 4-year period, indicating no negative effects from negative primary prevention studies during this time period.

Figure 1.

Percentage of all patients recorded as receiving aspirin therapy. AA, aortic aneurysm; CKD, chronic kidney disease; CVD, cardiovascular disease; DM, diabetes mellitus; HLD, hyperlipidemia; HTN, hypertension; PVD, peripheral vascular disease.

Figure 2.

Percentage of patients with current cardiovascular disease (CVD) who are taking aspirin (ASA) versus patients with newly diagnosed CVD who were prescribed ASA within the first year of diagnosis.

Figure 3 displays the percentage of individuals recorded as using aspirin with a new diagnosis of CVD risk factors or CVD equivalency during each period. In all cases the percentage of the population initiating aspirin therapy within a year of a new diagnosis went up between 2007 and 2011.

Figure 3.

Percentage of all patients prescribed aspirin within 1 year of new diagnosis. Arrows indicate corresponding time of study publication or guideline change. AA, aortic aneurysm; ADA, American Diabetes Association; AHA, American Heart Association; ATTC, Antithrombotic Trialists' Collaboration; CKD, chronic kidney disease; CVD, cardiovascular disease; DM, diabetes mellitus; DOPPS, Dialysis Outcomes and Practice Patterns Study; HLD, hyperlipidemia; HTN, hypertension; JPAD, Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes; POPADAD, Prevention of Progression of Arterial Disease and Diabetes Trial; PVD, peripheral vascular disease.