Association of Framingham cardiovascular disease risk scores with 10-year risk of cardiovascular mortality: a retrospective cohort study in South India

Background: Few cohort studies examine the association of cardiovascular risk scores with cardiovascular mortality in India. This study assessed the association of baseline Framingham Risk Scores (FRS) with 10-year incidence of fatal CVD events in rural Tamil Nadu, India. Methods: Using a retrospective cohort study design, we analysed the association of baseline FRS categories assessed in 2011-12 through a STEPS risk factor survey, with CVD deaths over 10 years. Causes of death for the survey participants aged 30–64 years at baseline (2011–12), were obtained through established vital event surveillance, while baseline FRS CVD scores were calculated using original and published recalibration equations. Results: 3418 participants (1480 males, 1938 females), free of CVD at baseline, were followed up for mortality for 10.22 years (median). The CVD mortality rate was 3.01 per 1000 person-years among males and 1.36 in females. Those with baseline original lipid-based FRS ≥20 % had higher CVD mortality risk (Hazard Ratio males: 11.18, 95 % CI: 4.67–26.79; females: 17.51, 95 % CI: 6.07–50.55) compared to those with scores <10 %, with similar results using recalibrated scores. Discrimination statistics (Harrell's C) were 0.755 and 0.751 for original and recalibrated lipid-based scores in males, compared to 0.734 and 0.842 in females. Conclusions: FRS had good predictive validity for cardiovascular mortality in a rural Indian population, confirming its clinical usefulness.