NEW ORLEANS - A Duke University Medical Center analysis of a Council for Affordable Quality Healthcare (CAQH) study of more than 15,000 insured patients has shown that during the year after suffering a heart attack, less than half of the patients had been taking beta blockers regularly.
This is a disturbing finding, the researchers said, since numerous clinical trials have proven the effectiveness of beta blockers in reducing the risk of future heart attacks and improving survival.
Duke performed its independent analysis of study data collected by CAQH, Washington, D.C., a not-for-profit alliance of more than 20 leading health plans and networks, providing health-care coverage to more 100 million Americans.
"While many studies have shown improvements in doctors' frequency of prescribing beta blockers at discharge after heart attacks, very few studies have looked at the long-term adherence to the drug," said Judith Kramer, M.D., principal investigator of the Duke Center for Education and Research on Therapeutics (CERTS) at the Duke Clinical Research Institute. "In the study, despite having prescription and commercial insurance coverage, less than 50 percent of this large population had been taking beta blockers regularly over the first year after their heart attack.
"In order for the proven benefits of these drugs to be realized, we need to focus our efforts on increasing patient adherence to the therapy," she continued.
Kramer presented the results of her analysis March 9, 2004, at the annual scientific sessions of the American College of Cardiology.
Beta blockers are a class of drugs that blunt the stimulatory effects of epinephrine and norepinephrine, the so-called "fight-or-flight" hormones. By blocking the effects of these hormones, beta blockers reduce the stress on the heart, and during exertion, they limit the increase in heart rate and so reduce the demand for oxygen.
Numerous studies have shown that approximately 90 percent of heart attack patients are receiving prescriptions for beta blockers at discharge from the hospital, the researchers said.
"CAQH has developed a coordinated effort among multiple health plans to conduct one of the largest studies to date of long-term beta blocker adherence," said Donald Fetterolf, M.D. chair of CAQH Measurement Work Group, medical director of Highmark BlueCross and BlueShield and co-author of the study.
"Beyond advancing knowledge and science CAQH will utilize the information to develop and implement appropriate interventions to help heart attack survivors achieve the benefits of this important and life-saving drug," he said.
The researchers identified 15,070 patients in 44 states where CAQH had both administrative and prescription data. In terms of insurance type, 73 percent were covered by commercial insurance plans, while the remaining 27 percent were covered by the Medicare+Choice plan. The data used was for calendar year 2001.
In the patients who survived one year after their heart attack, researchers measured the proportion of patients who had been taking beta blockers for at least 75 percent of the time for periods of three, six, nine and 12 months after their heart attack.
"We found a declining proportion of patients were adherent to beta blockers over time from hospital discharge in all insurance products and all geographic regions," Kramer said.
Specifically, 55 percent of patients had been taking beta blockers regularly during the first three months. However, looking over the full year after heart attack, only 46 percent of patients had been taking beta blockers at least 75 percent of the time.
"For drugs like beta blockers, adherence is very important, since patients need to take the drug for years after their heart attack in order to get the benefits," Kramer said.
The researches believe that reasons for the declining adherence are probably many and complex.
"Many patients do not realize, or were not told, that these drugs need to be taken for years," Kramer said. "For others, it could be an economic issue, since many of these patients tend to be older and take many other prescription medications. We obviously need to conduct further research to better understand the reasons why patients stop taking the drugs."
The researchers are now adding data for calendar year 2002, which they hope will provide additional insights in beta blocker use in the U.S., particularly how the usage differs by age and gender.
Kramer's analysis was supported in part by a cooperative grant from the CERTS program and the Agency for Healthcare Research and Quality.
The Centers for Education and Research on Therapeutics (CERTs) demonstration program is a national initiative to conduct research and provide education that advances the optimal use of therapeutics, including drugs, medical devices, and biological products. The program, which consists of seven centers and a coordinating center, is administered as a cooperative agreement by the Agency for Healthcare Research and Quality (AHRQ), in consultation with the U.S. Food and Drug Administration (FDA).
The source of this article release is http://www.dukehealth.org