Practice of Epidemiology Clinical Usefulness of the Framingham Cardiovascular Risk Profile Beyond Its Statistical Performance The Tehran Lipid and Glucose Study

The utility of a risk function in clinical practice is an important concept that has received insufficient attention. The authors evaluated the clinical usefulness of the Framingham risk function (FRF) for cardiovascular disease in a Middle Eastern population (2,640 men and 3,584 women aged 30–74 years) free of cardiovascular disease at baseline in 1999. They calculated the net benefit fraction for treatment of subjects with an estimated 10-year risk of ≥10% and also ≥20%, where the net benefit fraction is a weighted sum of true-positive and false-positive rates divided by incidence, as estimated by Kaplan-Meier analysis. The authors drew a decision curve by plotting the net benefit fraction against a wide range of risk thresholds for treatment. The cumulative incidence of cardiovascular disease was 7.6% and 12.3% in women and men, respectively. The FRF had a C index of 0.832 in women and 0.785 in men with a reasonable calibration. On the basis of the net benefit fraction, about 50% of the incidence in men and women could be appropriately treated by using the 10% threshold; however, the FRF was not useful at the 20% threshold, especially in women. In both genders, usefulness of the FRF was as good as the function derived directly from Tehrani data with the same variables; however, it could be useful in low thresholds for treatment.