Half of older adults in US now taking aspirin

A national survey suggests that slightly more than half of the older adults in the United States are now taking a daily dose of aspirin, even though its use is not recommended by the Food and Drug Administration for most people who have not yet had a heart attack or stroke.

The analysis was published today in the American Journal of Preventive Medicine. It observed that aspirin use is continuing to surge, especially among adults who are using it for "primary prevention," meaning in order to prevent an initial cardiovascular event, and in some cases to prevent cancer.

In this survey of more than 2,500 respondents aged 45-75, 52 percent reported current aspirin use, and another 21 percent had used it at some point in the past. The average age of respondents in the survey was 60. A different report found that aspirin use increased 57 percent between 2005 and 2010.

Aspirin is a blood thinner and can cause bleeding events, which is a primary reason some medical experts recommend caution in its use, even at the "baby aspirin" dose of 81 milligrams often used for disease prevention. The FDA has determined that in primary use to prevent a first heart attack or stroke, for every such event that's prevented, there's approximately one major bleeding event that's caused, such as gastrointestinal bleeding.

Largely on that basis, they have concluded physicians should routinely recommend its use only to patients that have already had a heart attack or stroke. But this study found that 81 percent of older adults who are now using aspirin have not had a heart attack or stroke, and are taking it for primary prevention.

"The use of aspirin is still a very contentious issue among medical experts," said Craig Williams, a pharmacotherapy specialist with the College of Pharmacy at Oregon State University, and lead author of the new report.

"There's no doubt that aspirin use can have value for people who have experienced a first heart attack, stroke or angina," said Williams, a professor in the Oregon State University/Oregon Health & Science University College of Pharmacy. "The data to support that is very strong. The support of its use in primary prevention is more of a mixed bag.

"But this survey clearly shows that more and more people who have not experienced those events and are not technically considered at high risk by the FDA are also deciding to use aspirin, usually in consultation with their doctors."

Aside from cardiovascular events, some studies have suggested a role for aspirin in preventing cancer, Williams said, especially colon cancer. That has further increased interest in its use, he said.

While the FDA takes a more cautious stance, Williams said, some other professional organizations, such as the U.S. Preventative Services Task Force, says aspirin use may be appropriate for primary prevention in people with serious risk factors for cardiovascular disease, such as high blood pressure, high cholesterol, smoking or diabetes. Objective criteria for aspirin use in those patients are based on the number of the risk factors, the age and gender of the patient.

Surveys such as this are needed to help determine how people are managing their own health, Williams said, since aspirin is an over-the-counter medication and its use cannot be determined solely by medical records. And the findings suggest that tens of millions of Americans have reviewed the issues involved, often discussed it with their doctors, say they know what they are doing - and decided to use aspirin.

Among the findings of the report:

• Several markers of healthy lifestyle choices were also associated with aspirin use.
• The strongest predictor of regular aspirin use was a patient having discussed aspirin therapy with a health care provider.
• About 35 percent of people who don't objectively have risk factors that might merit aspirin therapy still use it.
• About 20 percent of people who have already had a heart attack or stroke, and should be on aspirin therapy, do not use it.
• A majority of both current and previous aspirin users rated themselves as being somewhat or very knowledgeable about it.
• Among aspirin users, the reasons cited for its use by respondents was for heart attack prevention, 84 percent; stroke prevention, 66 percent; cancer prevention, 18 percent; and prevention of Alzheimer's disease, 11 percent.
• Significant predictors of aspirin use included people who were physically active, ate healthy foods, had achieved a healthy weight, managed their stress, tried to quit smoking, and/or had undergone health screenings.