G rover et al1 used the Coronary Heart Disease Prevention Model to calculate the potential gains in life expectancy from two lifestyle changes: reduction in intake of saturated fat and smoking cessation. The Model is based on logistic regression data from the Framingham Heart Study,2 the gains in life expectancy being calculated by applying preintervention and postintervention levels of total cholesterol and smoking vs nonsmoking status. Because the benefits of risk reduction may not be immediate, the authors recalculated gains in life expectancy with application of a 2- to 4-year lag period.
The problems inherent in this approach are clear from the meta-analyses of major intervention studies for hypercholesterolemia3,4 and hypertension.5 From these overviews, two things become clear: (1) the reversibility of risk for coronary heart disease and stroke may be less than complete, particularly during the early stages of intervention; and (2) effects on noncardiovascular
Yudkin JS. Calculating Gains in Life Expectancy With Risk Factor Reduction. Arch Intern Med. 1995;155(12):1329-1330. doi:10.1001/archinte.1995.00430120123017