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(Circulation. 1995;91:2855-2856.)
© 1995 American Heart Association, Inc.

Articles

The Calcium Channel Blocker Scare

Lessons for the Future

Claude Lenfant, MD

From the National Heart, Lung, and Blood Institute, Bethesda, Md.

	Introduction

Top Introduction

 
The recent panic over use of calcium channel blockers to treat hypertension illustrates the crucial role played by the communication (or miscommunication) of research results to the public. As most readers are aware, the situation was triggered by presentation of a case-control study at the American Heart Association (AHA) 35th Annual Conference on Cardiovascular Disease Epidemiology and Prevention. The study, which was funded by the National Heart, Lung, and Blood Institute (NHLBI), observed that rates of heart attack were higher among hypertensive patients taking a calcium channel blocker than among patients taking a diuretic or a ß-blocker. The press release issued by the investigator's institution noted that the increased heart attack risk associated with calcium channel blockers might be as high as 60%. Although the investigator was interviewed by the press and some of the reporting reflected a balanced perspective, many alarming stories were printed and broadcast. Headlines such as "Drug for Blood Pressure Linked to Heart Attacks: Researchers Fear 6 Million Are Imperiled" generated considerable public concern.

At the heart of the problem was a misunderstanding of the "60%" statistic. Some of the early reports failed to explain that it was an estimate of relative risk. It was not clear to patients taking calcium channel blockers that their immediate risk of heart attack was, in fact, low. Many early reports also lacked perspective on the study methodology and its limitations.

The resultant anxiety among hypertensive patients and others taking calcium channel blockers was understandable. Hundreds of patients telephoned the NHLBI, the AHA, the Food and Drug Administration, and their physicians. Some stopped taking their medication. Prescribing physicians, in turn, were frustrated and angered by the lack of information they had on the study.

The NHLBI, the AHA, and the investigator issued statements designed to put the study in perspective. The NHLBI statement, for example, noted that "even if the study's results are confirmed, the immediate risk of heart attack for an individual from calcium channel blockers would be low. ... This type of study, although useful, cannot provide definitive information on the effectiveness and long-term safety of a class of drugs." All of the statements referred to the need for clinical trials to resolve the matter. Indeed, the ongoing NHLBI-supported Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is addressing this very issue.

After several days of panic, a second round of media reports was issued that provided the needed context. The volume of phone calls diminished. Unfortunately, the damage had been done—the public had been confused and frightened.

This incident was certainly not the first time that news reports on a scientific study lacked meaningful perspective and interpretation. Media analysts have noted that this problem is due, in part, to the nature of news reporting. As The Washington Post ombudsman wrote in a March 26, 1995, column on the calcium channel blocker scare, "What was missing—and what caused newspapers to overreact to the story and patients to panic—is what often gets lost when journalists on deadline translate science: context and implications."

The problem can only be expected to escalate as medicine and science receive ever-widening media attention. The current trend is toward providing coverage not only of major medical meetings and journals but also of smaller scientific meetings focused on epidemiological or basic research and specialty journals. These increased opportunities for reporting on research naturally generate increased opportunities for misinterpretation.

At the same time, public interest in scientific and medical news continues to grow. A 1993 telephone survey of 1250 American adults commissioned by the Scientists' Institute for Public Information found widespread attention to scientific news. Despite the public's avid consumption of scientific and medical news, scientific knowledge is limited. Only 15% of Americans demonstrate even the slightest understanding of the process of scientific research, according to a recent survey prepared for the National Institutes of Health (NIH). Thus, scientists and the media share a tremendous responsibility to help the public interpret scientific research.

What measures can investigators take to prevent their own research from being misinterpreted, oversimplified, or exaggerated? When we are considering issuing a press release or discussing research findings with reporters, the following checklist of questions can serve as a reminder of potential pitfalls:

Would the statements made to the press be appropriate in a scientific paper?

Are the study findings placed in the context of any limitations of the research?

Are the statistics and their meaning carefully explained?

Do certain concepts (eg, relative risk) require elaboration?

It is also valuable to consider how the public, patients, and physicians will likely interpret—or misinterpret—the news:

Will it engender needless worry or, alternatively, raise false hope because of exaggerated promises?

Is it clear what the research may mean to an individual's health?

What specific populations might be affected and how?

Guidance on communicating these issues can usually be obtained from the grantee institution's or funding organization's public affairs office. It is important to work with the NIH or other funding sources in a timely manner to ensure that press releases are coordinated.

The NHLBI is committed to communicating research results and their implications to the public accurately and effectively. Our partnership with the scientific community can go far toward enhancing public understanding of science and medicine.

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