Improving the prediction of coronary heart disease to aid in the management of high cholesterol levels: what a difference a decade makes.

CONTEXT

A patient's coronary heart disease (CHD) risk must be correctly classified to successfully apply risk-based guidelines for treatment of hypercholesterolemia.

OBJECTIVE

To determine the classification accuracy of the National Cholesterol Education Program (NCEP) CHD risk-stratification system and compare it with a simple revised system that gives greater weight to age as a CHD risk factor.

DESIGN

Modeling of 10-year CHD risk, using equations from the Framingham Heart Study applied to a cross-sectional survey of the US population.

SUBJECTS

The 3284 subjects aged 20 to 74 years surveyed in the Second National Health and Nutrition Examination Survey (1978-1982) who had fasting lipid levels measured.

MAIN OUTCOME MEASURES

The area under the receiver operating characteristic curve (AUC) for 10-year CHD risk for the NCEP and revised scales.

RESULTS

Among all adults with a low-density lipoprotein cholesterol value of at least 4.1 mmol/L (160 mg/dL), the NCEP system showed fairly good discrimination (AUC=0.90), though there was a substantial decline among men 35 to 74 years old and women 55 to 74 years old (AUC=0.81). By contrast, the revised system showed superior performance in all hypercholesterolemic adults (AUC=0.94-0.97) as well as in the subgroup of men 35 to 74 years old and women 55 to 74 years old (AUC=0.94-0.96).

CONCLUSIONS

Simple modifications of the NCEP treatment criteria result in a substantially improved ability to discriminate between higher and lower CHD risk groups. Unlike the NCEP system, this revised system retains its classification ability in all age groups studied.