February 25, 2015 – Risk Factor Change
Anchor lead: Why do heart disease risk calculators overestimate risk? Elizabeth Tracey reports
Heart disease risk calculators attempt to take a group of risk factors and use them to pinpoint an individual’s risk for heart disease, then strategies are employed to minimize it, but a comparative study of these tools by Johns Hopkins preventive cardiologist Michael Blaha and colleagues found heart disease risk was overestimated. Blaha says the most likely reason is the risk factors themselves.
Blaha: Risk factor relationships may be changing. Many of the risk factors are binary, for example you either smoke or you don’t smoke. But we know now that people smoke less than they used to, the tar content of cigarettes has changed, and maybe the smoking term may not be as well calibrated now compared to when it was derived generations ago. Background things that we don’t measure have changed: trans fat intake, salt intake, public smoking bans, secondhand smoke, those have all changed and are not necessarily captured in the risk factors in the equations, which might explain why we’re seeing some overestimation of risk now. :30
At Johns Hopkins, I’m Elizabeth Tracey.