Objective-To compare the relative accuracy of cardiovascular disease risk p
rediction methods based on equations derived from the Framingham heart stud
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
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