Roughly one quarter of people discharged after a myocardial infarction may not fill one or more new prescriptions, significantly increasing their risk for death in the first post-infarction year, according to an article in the February 26 issue of Circulation.

"Taking medications, such as aspirin, beta blockers, statins or angiotensin-converting enzyme inhibitors, after having a heart attack is a powerful way to prevent future heart attacks and death, but no research to date has documented these patients' compliance," said Cynthia A. Jackevicius, B.Sc.Phm., M.Sc., Pharm.D., lead author of the study.

Canadian researchers from the Institute for Clinical Evaluative Sciences in Toronto, Ontario, used data from a population-based acute myocardial infarction registry that linked to prescription drug claims, vital statistics, use of physician services and hospital discharge databases. The primary data source for patient information was the Enhanced Feedback for Effective Cardiac Treatment (EFFECT) study registry, which included hospital records from 104 acute care hospitals in Ontario from 1999?2000 to 2000-2001.
The primary outcome was one-year mortality.

"We looked at data from 4,591 patients in Canada who had been in the hospital and the 12,832 prescriptions that were written as a result of their having had heart attacks," said Jackevicius, a researcher at ICES. "From the data, we were able to see what people were supposed to be filling, as far as prescriptions to prevent heart attack, and whether those prescriptions were filled or not."

To analyze drug adherence, researchers linked to the Ontario Drug Benefit prescriptions claims database. Researchers excluded drugs patients were taking prior to hospital admission.

The researchers found that one in five of all prescriptions were not filled after patients left the hospital, and that only three out of every four patients filled all their prescriptions.

"So, 25 percent of the patients did not fill their prescriptions completely or at all," Jackevicius said.

Jackevicius said patients who filled none of their prescriptions had an 80 percent higher chance of dying in the year following discharge than those who filled all their prescriptions. And if they only filled some of their prescriptions, they had about a 40 percent increased chance of dying in the first year versus if they filled all their prescriptions.

Patients who were educated in the hospital about their prescriptions were more likely to fill theirs. Those who filled their prescriptions were also most likely to do so within one week of leaving the hospital, Jackevicius said.

"The healthcare team, including physicians, nurses and pharmacists, should look at this data and take steps to ensure that patients are educated about their prescriptions to prevent future heart attacks before they leave the hospital," she said. "Consumers should also advocate for themselves, making sure they are educated. Providers might consider making follow-up calls to patients within the first week or two after their hospital stays to remind them to fill their prescriptions, if they haven't."

Future research should also explore why patients don't necessarily fill their
prescriptions, Jackevicius said.