In November 2014, several major media, including CBS News, TIME magazine and, reported that a large clinical trial in Japan found that a daily, low-dose aspirin did not significantly reduce the incidence of heart attack and stroke in older Japanese patients with multiple risk factors.

The results contradict the prevailing popular understanding about the absolute benefits of low-dose aspirin—a juicy news hook picked up by the news media when the results were presented at the American Heart Association meeting in mid-November and published simultaneously in JAMA (Journal of the American Medical Association).


Given what seems to be contradictory information, should you take a baby aspirin daily or not to prevent a heart attack or stroke? The American Heart Association, the American Stroke Association, the American College of Cardiology and the American Association of Neurology all say yes, based on guidelines published in 2015 on the use of aspirin in the primary prevention of stroke.

“Their recommendations were based on a total of 954 pieces of medical literature and studies,” says David Shute, MD and GreenField Health Medical Director, who practices at GreenField’s Westside office, “and they endorse the use of low-dose aspirin in individuals whose risk of having a heart attack or stroke within the next ten years is 10% or greater.”

These odds, he explains, are based on several high-risk factors—namely, high blood pressure, high blood cholesterol, smoking, obesity, diabetes, and physical inactivity.

You can also do your own assessment with an interactive risk calculator that estimates your 10- or 30-year risk compared with others in your age group based on factors such as your weight, activity level and smoking history. This is the same tool used by your clinician; it stems from research by the Framingham Heart Study, which has compiled extensive statistics since 1948 for cardiovascular disease risk.

But what about the Japanese study results? It's challenging for patients to make sense of studies that are widely reported but not fully explained. “Individual studies are fraught with problems,” says Shute. A view held by JAMA's editors, too, as described in an editorial in the 11/17/2014 issue.

“If we were to manage people’s healthcare by individual clinic trial results when they come out, there’s a high likelihood that we’ll cause more harm than benefit for our patients,” Shute says.  “Individual clinical reports are often times studied for years after they are published.  In some cases the study conclusions are found to be erroneous, and in other cases totally new conclusions can be drawn by looking at subsets of the study data.”

Our practice philosophy at GreenField Health is to look more broadly at a clinical issue using consensus statements or guidelines from large, well respected professional medical societies. These typically involve many academic physicians as well as non-physician clinical professionals, including pharmacists. This approach considers a large volume of clinical trials for a particular topic, grades the evidence based on the quality of the research, and makes concluding statements. These give practicing physicians high quality, evidence-based guidance on how to care for patients. 

"Good medicine takes the long view when it comes to research," Shute says, "so keep this in mind when you see media coverage about what the latest study says because oftentimes you're not getting the big picture--only one tiny piece of it."