While some have criticized the U.S. Preventive Services Task Force's (USPSTF) revised guidance for daily aspirin use as "flip-flopping," medical experts say reviewing and updating guidance are important parts of keeping up with new scientific research, Tara Parker-Pope writes for the New York Times.

Cheat sheets: Evidence-based medicine 101

USPSTF issues new draft guidance on daily aspirin

USPSTF earlier this month issued draft guidance advising against the use of a low, daily dose of aspirin to prevent a first heart attack or stroke for certain populations—deviating from its 2016 guidelines.

Under the draft guidance, adults ages 40 to 59 years old who have at least a 10% risk of a cardiovascular event over the next 10 years—but who have not previously had a heart attack or stroke—should consult with their doctor to determine if they should start taking low-dose aspirin as a preventive measure, although the panel concluded that such dosage may confer a small benefit.

And for people ages 60 and older, the draft guidance strongly discouraged the use of low-dose aspirin to prevent a cardiovascular event, citing new research indicating there's no net benefit to doing so given the increased risk of a bleeding event, including a gastrointestinal bleed or a brain bleed.

According to Parker-Pope, these revised aspirin recommendations have garnered some criticism, especially as people attempt to keep up with shifting pandemic guidance on masks and booster shots.

"Wait long enough, and smoking and heavy cream will be good for you," wrote Richard Koss, an economist in New York. "The vast majority of people are fed up with this sort of thing and, rightly, pay it no attention."

Medical experts say updated guidance should be reassuring

However, medical experts said patients should be reassured—not concerned—by the revised guidance, Parker-Pope writes, because it means even trusted medical guidelines are being reviewed and updated as scientific understanding changes.

"It seems like it happens overnight, but this is how science works," said Sophie Balzora, a gastroenterologist at NYU Langone Health. "If we had the same guidelines all the time, then the question would be: Are we really advancing science? Are we really learning more?"

Several experts also said the new aspirin guidance from USPSTF should be considered updated advice that improves on past guidance instead of a complete reversal. According to Parker-Pope, the task force has also previously updated guidance on colonoscopy and breast cancer screenings.

"The task force is just constantly re-evaluating based on what data [was] available," said Barron H. Lerner, a medical historian and professor of medicine at NYU Langone Health. "This might be seen as flip-flopping, but it is really making adjustments based on the evolving science."

"Things that we knew were right in the late '80s early '90s need to be rechecked to see if they're still right, given that we're all quite different than 30 years ago," said Adam Cifu, a professor of medicine at the University of Chicago. "It's a little uncomfortable that things don't stay the same forever, but it's good that medicine is checking itself."         

Parker-Pope notes that the U.S. population has significantly changed since early research suggested a benefit to using aspirin to prevent heart problems. For example, people now smoke less and have better treatments to control diabetes, high blood pressure, and high cholesterol—conditions that all affect the risk of heart attack and stroke. As a result, aspirin can still protect the heart, but doctors said the drug's benefits are now less pronounced, and its risks, although still low, are of greater concern.

"There's no longer a blanket statement that everybody who's at increased risk for heart disease, even though they never had a heart attack, should be on aspirin," said Chien-Wen Tseng, a member of USPSTF and the research director at the University of Hawaii John A. Burns School of Medicine.

Tseng added that she hoped the revised guidance would encourage more people to talk about their heart health with their doctors. "One of the key messages we need to get out is that aspirin isn't like a vitamin," Tseng said. "There are potential benefits and potential risks. Everybody should be having a conversation with their clinician instead of just opening a bottle and taking aspirin automatically because they've reached a certain age."

"We need to be smarter at matching primary prevention to the people who will benefit the most and have the least risks of harm," Tseng said. (Parker-Pope, New York Times, 10/24)