Despite guidelines, prevalence of aspirin use high among populations at an increased risk for harm

Older adults in the U.S. may be overdoing it with low-dose aspirin therapy, particularly if they have a diabetes diagnosis, researchers reported.

In a cross-sectional analysis of national data, 61.7% of older U.S. adults (mean age 69.9) with diabetes versus 42.2% without diabetes used aspirin. Among those without diabetes, aspirin use was significantly greater in older age categories versus the reference (ages 60-69) in a model that adjusted for BMI, age, race/ethnicity, sex, education, and cardiovascular disease (CVD) risk status (ages 70-79, odds ratio 1.50, 95% CI 1.23 to 1.83; ≥80, OR 1.59, 95% CI 1.24-2.04), according to Rita R. Kalyani, MD, of Johns Hopkins University School of Medicine in Baltimore, and co-authors.

In that same model (model 3), the likelihood of aspirin use for primary prevention in those at high risk for CVD versus those at low risk wasn’t different among older adults with diabetes, but was significantly higher in those without diabetes, they reported in JAMA Network Open.

Additionally, the “sex differences in aspirin use for those with diabetes were noteworthy,” the authors pointed out. They found that women with diabetes were less likely to use aspirin for primary prevention.

In short, the current findings “indicated that more than 20% of individuals in the analysis with low cardiovascular risk use daily aspirin. This percentage rises to greater than 50% of the individuals older than 80 years,” but this “rate of aspirin use is poorly justified by current evidence and would seem likely to be causing more harm than good,” pointed out Wilson D. Pace, MD, of the DARTNet Institute, Aurora, Colorado, in an invited commentary accompanying the study.

That evidence includes a “B” grade recommendation from the U.S. Preventive Services Task Force (USPSTF) for aspirin use for preventing CVD and colon cancer in people ages 50 to 59, which was downgraded to an “I” grade for those ages >70 based on lack of evidence; the ASPREE and ARRIVE trials, neither of which had positive outcomes for daily aspirin use and primary prevention; and the ASCEND trial, which did show a CV benefit for patients with diabetes, but with an increase in major bleeding events.

These data don’t make it any easier for clinicians to determine how to counsel their patients about daily aspirin use, Pace acknowledged. The “USPSTF simulations indicate that the overall benefit from low-dose aspirin increases over time, particularly with respect to cancer prevention,” he explained. Additionally, those ages >70 most likely started daily aspirin at a younger age, so “[s]topping a therapy on which an individual appears to be doing well can be a much harder decision for both patient and clinician than not starting the treatment in the first place.”

Pace urged clinicians to regularly review and discuss the pros and cons of daily aspirin use with their patients. In 2019, the American Heart Association/American College of Cardiology updated its guidelines, no longer recommending aspirin for CVD prevention in adults ages ≥70, or for those at a higher risk of bleeding. Major institutions such as the Mayo Clinic, the Cleveland Clinic, and Harvard Medical School offer online guidance for patients.

Kalyani’s group evaluated data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018, settling on 7,103 individuals (ages >60, 45.2% men; 75.8% white) with and without diabetes. The participants completed a questionnaire on preventive aspirin use.

“Preventive aspirin use was defined as participants’ self-reported use of low-dose aspirin therapy based on their physician’s advice or their own decision,” they explained.

Statistical analyses were done from July 2019 to April 2021, and logistic regression models were used to assess the association of diabetes status with aspirin use in the overall population and primary prevention subset with an unadjusted model (model 1), a model that adjusted for age, race/ethnicity, sex, education, and CVD risk status, and model 3.

Kalyani and co-authors reported that an estimated 9.9 million U.S. adults, ages ≥70 reported use of aspirin therapy for primary prevention, whether they had a diabetes diagnoses or not. They also found that men without a history of CVD but with diabetes were more likely to take aspirin and have a higher mean waist circumference (mean 110.2 cm or about 43 inches).

And women versus men with diabetes were less likely to be using aspirin for primary prevention (OR 0.63, 95% CI 0.48-0.83). “Sex disparities in aspirin use could be due to several factors, including less awareness of CVD risk among women, misconceptions that women are protected against CVD, and concerns that aspirin is less effective for women than for men, an idea that has been refuted by recent studies,” Kalyani’s group wrote.

Study limitations included self-reported data and the fact that the NHANES questionnaire did not differentiate between aspirin use for cancer prevention versus CVD prevention.

Still, the findings were in line with a previous NHANES analysis, Kalyani and co-authors noted. The authors of the latter study also stressed that “health care practitioners [need] to ask their patients about ongoing aspirin use and to advise them about the importance of balancing the benefits and harms, especially among older adults and those with prior peptic ulcer disease.”

Whether a forthcoming update to the USPSTF recommendations on aspirin use for primary prevention will change clinicians’ and patients’ minds remains to be seen, according to Kalyani’s group. Per the task force website, the public comment period on the updated recommendation was closed as of May 2020.

  1. Use of aspirin for primary prevention of cardiovascular disease (CVD) increased with older age and higher CVD risk among people without diabetes, while it was uniformly high among those with diabetes.

  2. Older adults may be overusing aspirin therapy despite revised guidelines that discourage routine use of aspirin in adults ages ≥70.

Shalmali Pal, Contributing Writer, BreakingMED™

Kalyani reported no relationships relevant to the contents of this paper to disclose. A co-author reported support from the American Federation for Aging Research Medical Student Training in Aging Research Summer Program.

Pace reported no relationships relevant to the contents of this paper to disclose.

Cat ID: 12

Topic ID: 76,12,282,494,730,12,255,669,918