September 2006 - Fewer than half of the patients who were prescribed beta blocker drugs following a heart attack and who had some prescription drug coverage were regularly taking them during the first year after leaving the hospital, according to a Duke University Medical Center analysis of more than 17,000 patients nationwide.
This low rate of adherence is disturbing, since numerous large-scale clinical trials have proven that beta blockers can reduce the risk of future heart attacks, the researchers said. They said the finding also suggests that cost may not be the only issue that influences whether heart attack patients continue to take the drugs.
Beta blockers blunt the normal stimulatory effects of the hormones epinephrine and norepinephrine on the heart, thereby reducing stress on the heart. The drugs also limit the increase in heart rate and reduce the heart's need for oxygen when people exert themselves.
In the study, the researchers found that only 45 percent of heart attack patients regularly took beta blockers during the first year after leaving the hospital. The biggest percent drop in adherence occurred during the initial months after discharge, suggesting that physicians need to step up efforts during this period to improve usage rates, the researchers said.
In particular, younger women with commercial insurance were less likely to continue taking beta blockers following a heart attack, compared to men their age and to older women, the study found.
"In the population of patients we studied with health insurance and prescription drug coverage, we found adherence to beta blockers during the first year following a heart attack to be quite poor, indicating that factors other than the cost of the medicine are important to long-term adherence," said study leader Judith Kramer, M.D., an associate professor at the Duke University Medical Center.
The researchers published the findings in the September 2006 issue of the American Heart Journal. The study was funded by the Council for Affordable Quality Healthcare, a coalition of more than two dozen of the nation's largest health plans and networks representing more than 100 million Americans.
According to Kramer, physicians working in hospitals have improved their prescribing of medicines, such as beta blockers, proven by clinical trials to be effective in forestalling heart attacks. After patients are discharged, however, they face myriad medical and social challenges that can affect whether they continue to take their medicines over the long term.
"Once discharged, they can return home to a different and complex set of issues," she said. "Patients often do not realize, or it is not made clear to them, that beta blockers must be taken for the rest of their lives."
The solution for addressing this poor rate of adherence lies, at least in part, with the health care delivery system, Kramer said.
"Strategies to maintain adherence must focus not only on community physicians to maintain prescribing, but also on patients and their families," she said. "And as our results suggest, these strategies need to begin within the first month or two after hospital discharge."
For their analysis, the researchers used data collected by the Council for Affordable Quality Healthcare to complement a cardiovascular quality initiative. Each participating health plan had submitted its data in the aggregate to the council.
"This study strongly demonstrates the value of aggregating claims data to generate a more complete picture of compliance challenges," said Robin J. Thomashauer, the council's executive director. "We hope the findings encourage health plans, health care providers and other stakeholders in the health care industry to collaborate on new approaches for motivating patients to take their medicine as prescribed."
The researchers used the collective data about prescriptions from 17,035 patients. For patients who had survived one year after their heart attack, the researchers used prescription claims to estimate patients' regular usage of beta blockers for one, three, six, nine and 12 month intervals following hospital discharge.
"Adherence is very important, since patients need to take the drugs for the rest of their lives in order to get the benefits," Kramer said.
The National Committee for Quality Assurance, an organization that accredits commercial health insurance plans, recently began using six-month adherence to beta blockers after a heart attack as one measure in assessing how effectively the health plans are serving their members. The group has adopted the Council for Affordable Quality Healthcare's methodology for collecting data.
Other members of the research team included, from Duke, Bradley Hammill, Kevin Anstrom, Nancy Allen LaPointe and Eric Peterson, and, from the Council for Affordable Quality Healthcare, Donald Fetterolf, Richard Snyder, John Charde and Barbara Hoffman.
Source: Duke University Medical Center