Validating the Framingham Hypertension Risk Score: A 4‐year follow‐up from the Brazilian Longitudinal Study of the Adult Health (ELSA‐Brasil)
Danielli Haddad Syllos, Vinícius F. Calsavara, Isabela M. Benseñor, Paulo A. Lotufo
Abstract
The Framingham Heart Study published an equation that permits to estimate the 4-year incidence of hypertension among adults. In Brazil, only the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) of 15 105 men and women aged 35-74 years enrolled in 2008-2010 has data that can validate the Framingham Risk Score for Hypertension and create a new equation according to the Brazilian population. We examined the predictive performance of the Framingham Risk Score for Hypertension in the ELSA-Brasil using as an outcome variable, the 4-year incidence of hypertension. We split randomly the 8027 participants who participated in the second visit (2012-2014) and without hypertension at baseline in derivation data set (n = 4825; 60%) and a validation data set (n = 3202 participants; 40%). The area under the curve for Framingham Risk Score for Hypertension and ELSA-Brasil Risk Score was relatively similar. Hosmer-Lemeshow chi-squared statistic applied for the Framingham Risk Score was 3.78 (P-value = .876) and for our model was 8.22 (P-value = .41), disclosing good discrimination and calibration for both models. Even with these classification intervals, our model presents more underestimation of the risk, classifying 15% of the participants with new onset of hypertension in low risk vs 9% of the Framingham model and less overestimation of the risk, classifying 17% of the participants without hypertension as high risk vs 24% of the Framingham model. We concluded that the Framingham Risk Score for Hypertension has an acceptable performance when applied in the ELSA-Brasil population with good discrimination and calibration.