Comparative accuracy of cardiovascular risk prediction methods in primary care patients

Objective-To compare the relative accuracy of cardiovascular disease risk p rediction methods based on equations derived from the Framingham heart stud y. Design-Risk factor data were collected prospectively from subjects being ev aluated by their primary care physicians for prevention of cardiovascular d isease. Projected cardiovascular risks were calculated for each patient wit h the Framingham equations, and also estimated from the risk tables and cha rts based on the same equations. Setting-12 primary care practices (46 doctors) in Birmingham. Patients-691 subjects aged 30-70 years. Main outcome measures-Sensitivity, specificity, and positive and negative p redictive values of the Framingham based risk tables and charts for treatme nt thresholds based on projected cardiovascular disease or coronary heart d isease risk. Results-59 subjects (8.5%) had projected 10 year coronary heart disease ris ks greater than or equal to 30%, and 291 (42.1%) had risks greater than or equal to 15%. At equivalent projected risk levels (10 year coronary heart d isease greater than or equal to 30% and five year cardiovascular disease gr eater than or equal to 20%), the original Sheffield tables and those from N ew Zealand have the same sensitivities (40.0%, 95% confidence interval (CI) 26.6% to 57.8% v 41.2%, 95% CI 28.7% to 57.3%) and specificities (98.6%, 9 5% CI 97.2% to 99.3% v 99.7%, 95% CI 98.8% to 100%). Modifications to the S heffield tables improve sensitivity (91.4%, 95% CI 81.3% to 96.9%) but redu ce specificity (95.8%, 95% CI 93.9% to 97.3%). The revised joint British re commendations' charts have high specificity (98.7%, 95% CI 97.5% to 99.5%) and good sensitivity (84.7%, 95% CI 71.0% to 93.0%). Conclusions-The revised joint British recommendations charts appear to have the best combination of sensitivity and specificity for use in primary car e patients.