Patients who frequently miss a dose of heart medication may be more than twice as likely to have an adverse event such as myocardial infarction, stroke, or death than peers who take medication regularly, according to an article in the September 10 issue of the Archives of Internal Medicine.

The findings are important because they pinpoint the size of the problem, said study co-author Mary Whooley, MD, associate professor of medicine at the University of California at San Francisco. Just over 8 percent of the 1,015 patients surveyed said they fail to take their medicine at least 25 percent of the time.

“The next step is to figure out how we can change people’s behavior,” Whooley said. “It is so hard to convince people to lose weight, exercise and take their medicines as they’re supposed to. If we could figure out ways to motivate people to change, that would have tremendous public health consequences.”

Whooley and colleagues asked coronary heart patients taking part in a national study whether they took their medications as prescribed over the past month. Then they followed the patients for almost four years to see who died and who survived a myocardial infarction or stroke.

After the researchers adjusted the numbers to account for the effects of factors like depression and severity of illness, those who admitted not taking their medication more than 25 percent of the time were 2.3 times more likely to suffer serious problems - including death - than others. Close to 14 percent of patients who more regularly took their medications experienced cardiac events, compared with about 23 percent of those who more frequently skipped doses.

While it is possible that other factors could affect the health of those who do not take their medications consistently, it is still important for doctors to ask a “simple question” about whether patients follow medication instructions and to follow up if they don’t, said P. Michael Ho, MD, staff cardiologist at Denver VA Medical Center.