Abstract 3655: Esimating Lifetime Risk for Cardiovascular Disease in Men and Women: How well does the Framingham Risk Score Add Up?
Background: The AHA and ACC recommend summing sequential 10-year risk estimates as a surrogate for direct lifetime risk estimation. Because the accuracy of this method is unknown, we sought to compare this indirect method with a direct estimate of lifetime risk.
Methods and Results: We defined five mutually exclusive risk strata (all optimal risk factors, ≥1 not-optimal risk factor, ≥1 elevated risk factor, 1 major risk factor, or ≥ 2 major risk factors) based on a previously published algorithm for men and women at age 50 years. We entered combinations of risk factors corresponding to the definition of each stratum into the online Adult Treatment Panel III risk assessment tool. We created an indirect lifetime risk estimate for each risk stratum by summing the 10-year risk at ages 50-, 60-, and 70 years, comparing it to our previously published direct estimate of lifetime risk at age 50 years. Summed versus directly estimated lifetime risks for men in the 5 strata were: 30% vs 5%; 36% vs 36%; 46% vs 47%; 47% vs 50%; and 83% vs 69%. In women, the summing method substantially under-estimated remaining lifetime risks in most strata: 5% vs 8%; 7% vs 27%; 11% vs 39%; 12% vs 39%; and 32% vs 50%. Representative data from women are shown in figure⇓.
Conclusions: The indirect approach of summing 10-year risk estimates overestimated lifetime risk in men with low risk factor burden, but was generally accurate in men at higher risk. In contrast, the indirect approach substantially underestimated lifetime risk in women with any risk factors above optimal levels.