Report claims calculator overestimates risk

A risk calculator recently unveiled in guidelines by the American College of Cardiology (ACC) and the American Heart Association (AHA) may be flawed, according to the New York Times. The article claimed that two reviewers found that the calculator could overestimate risk by as much as 150 percent.

Expert panels published four prevention guidelines Nov. 12 that addressed cardiovascular risk assessment, lifestyle management, cholesterol treatment and managing overweight and obese adults. The risk assessment guideline included risk equations to predict atherosclerotic cardiovascular disease risk that were described as a linchpin for the cholesterol treatment and obesity documents.

According to the New York Times, Paul M. Ridker, MD, and Nancy Cook, MD, both of Brigham and Women’s Hospital in Boston, had been sent a draft of the risk assessment guideline by the National Heart, Lung, and Blood Institute to review. The institute was transitioning its role in the publication of such guidelines to the two cardiovascular societies. Ridker and Cook had led numerous randomized controlled clinical trials and have played key roles in developing cardiovascular risk models.

The reviewers reportedly identified problems with the risk calculator by applying it to data from patient populations with known outcomes. Based on those analyses they found the risk calculator could overestimate risk by 75 percent to 150 percent. The risk guidelines set a threshold of 7.5 percent or more for initiating treatment.

Donald Lloyd Jones, MD, co-chair of the risk assessment work group and chair of preventive medicine at Northwestern University Feinberg School of Medicine in Chicago, reportedly told the Times that “the researchers thought the committee had been given the professors’ responses” and that writing teams had revised documents based on reviewers’ comments.

Ridker and Cook discovered that problems remained when the guidelines were published online in Circulation and the Journal of the American College of Cardiology. The Lancet is scheduled to publish a commentary from the two reviewers on Nov. 19. In the meantime, members of the ACC and AHA have been meeting during the AHA’s ongoing scientific session in Dallas to coordinate a response, the Times wrote.