Data analysis by Bloomington-based HealthPartners has helped federal health authorities address a vexing question: Who should take daily aspirin to reduce heart disease risks, and who should not?
The answer came Monday, when the U.S. Preventive Services Task Force issued new advice on daily aspirin use, putting a finer point on what had been blunt guidance. The new advice recommends daily aspirin for adults aged 50 to 59 who have a life expectancy of at least a decade but also a 10 percent chance of a cardiovascular event such as a heart attack.
And it adds a caveat: Aspirin-takers should have only average risks for stomach bleeding, which can occur with regular consumption of the over-the-counter painkiller.
Americans aged 60 to 69 with the same risk profiles should consider aspirin only in consultation with their doctors, the influential task force said in its guidance, which was published in the Annals of Internal Medicine.
Previously, the task force recommended aspirin for men aged 49 to 79, and women aged 55 to 79, when their respective risks for cardiovascular problems or strokes were greater than their risks of aspirin-related complications.
Like the task force's controversial guidance on mammograms last year, Monday's recommendation reflected a complicated balancing of lives saved against medical risks.
"Our recommendation really highlights what the science tells us about the groups that are likely to benefit," said Dr. Kirsten Bibbins-Domingo, a San Francisco epidemiologist who is chairwoman of the U.S. task force.
The task force does not favor aspirin for people younger than 50 or older than 69.
The guidelines also reflect new evidence that aspirin reduces colon cancer risks.
Whether the new recommendation will affect doctors' advice to patients is unclear, but it could reduce aspirin usage among patients in their 60s and 70s.
The previous guideline was so broad that doctors might have overlooked discussing aspirin with elderly patients, given their other pressing medical needs — even if their electronic record-keeping systems reminded them to ask about it, said Dr. Rae Ann Williams, an internal medicine specialist at HealthPartners' Como clinic.
"When it's such a wide age range, I think it is more likely to get missed," she said.
Now the "risk-benefit discussion" can be more effective because it is tailored by age, said Williams, who expects patients will be reading about the new guidance and asking questions at their next appointment.
Even with the prior aspirin recommendation, in place since 2009, federal survey data showed that only 41 percent of doctors offered aspirin to patients who were eligible for it based on their age and heart disease risks.
The guidance is only for primary prevention, meaning for people with no prior cardiac events or colon cancers.
Netting out good and bad
Computer modeling at the HealthPartners Institute was key to the more precise recommendation issued Monday — amassing data from a variety of studies that tracked aspirin users and calculating the good outcomes and bad outcomes into a net conclusion.
Daily aspirin would prevent 225 nonfatal heart attacks, 83 nonfatal ischemic strokes and 139 cases of colon cancer, but would cause 284 severe stomach ulcers and 23 hemorrhagic strokes (due to its anti-clotting properties) if given to 10,000 men aged 50 to 59 who have a 10 percent risk of cardiovascular disease, the modeling found.
The estimated result would be 333 more years of life in this group of 10,000 men, and 588 more quality years of life — a measure of healthy years of life vs. years in which people suffer disabling complications from their diseases.
Results were similar for women in this age range, but weren't as surefire for men or women in their 60s — hence the recommendation that these older adults only consider aspirin in consultation with their doctors.
Such a nuanced recommendation would have been difficult without HealthPartners' predictive analysis, said Steven Dehmer, a research associate with the institute.
For every nonfatal heart attack spared by aspirin, or every stomach bleed it caused, the institute was able to predict long-term outcomes such as the likelihood of additional complications.
"Preventing a nonfatal heart attack might prevent a nonfatal stroke," he said. "There is a cascading of effects that can happen."
Patient pushback?
The task force is considered one of the most unbiased, credible sources of medical information in the United States, but it has been criticized by breast cancer advocates for its guidelines that pushed back the first mammograms for women with average breast cancer risks.
Bibbins-Domingo anticipates less resistance to the new recommendation, which addresses the bleeding risks that have concerned some people regarding aspirin. It also provides a single standard for aspirin usage, regardless of whether people want it for its cardiac or cancer prevention benefits.
"Patients are really making one decision about whether to take an aspirin," she said.
The recommendation did not include any economic pros and cons, though Dehmer said HealthPartners will soon publish such a cost analysis. Pharmacies charge anywhere from $10 to $15 for a bottle of 300 aspirin pills, or around 3 to 5 cents per pill.
Jeremy Olson • 612-673-7744
