VALIDATION OF THE SCORE (SYSTEMATIC CORONARY RISK EVALUATION) MODEL ADJUSTED TO ESTIMATE RISK OF FATAL AND NON-FATAL EVENTS IN A SOUTHERN EUROPEAN COUNTRY

Abstract

Objective: To conduct an external validation of the modified SCORE (Systematic COronary Risk Evaluation) model for low-risk regions to estimate risk of fatal and non-fatal events among asymptomatic individuals (primary prevention). Design and method: Nationally cross-sectional examination in an occupational cohort with an in-person interview including laboratory tests. Study participants were examined between 2006 and 2007 without previous cardiovascular disease. Main outcomes included fatal and non-fatal cardiovascular events over a 10-year follow-up period. Using already published SCORE risk equations to estimate ten-year risk of fatal cardiovascular disease for low-risk regions, the estimated score including non-fatal events was adjusted by multiplying by 4 in women and by 3 in men. The predictive accuracy of the risk estimated was assessed using both calibration and discrimination. Agreement between predicted and observed events across deciles of predicted risk was graphically evaluated. Discrimination was assessed by plotting the receiver operating characteristic curve and the C-statistic. Results: SCORE was computed for 228,986 subjects, mean age was of 48 (SD 6.2) years and 75.6% were men. Fatal and non-fatal events were recorded in 2.7% of men and 1% of women. Estimated C-statistic was 0.65. Risk scores calibrated well between first and eight deciles, with ratios expected to observed cases ranging from 0.7 up to 1.8, being represented almost 89% of the sample, and showed an overestimation of observed risk at the two highest deciles with ratios between 2 and 3. Conclusions: Estimated risk using SCORE equation for low risk countries adjusted with morbidity data showed a good calibration (it improves when calibration is calculated only with mortality data) and an acceptable discrimination.