Laboratory-based calculation of coronary heart disease risk in a hospital diabetic clinic

Aims To develop an estimation of risk of coronary heart disease (CHD) based on the Framingham equation for use in a diabetes clinic, given concerns about the accuracy of the Sheffield risk tables in this setting. Methods A computer program using the Framingham equation based on patients' age, sex, systolic blood pressure, smoking history, presence of diabetes and left ventricular hypertrophy was applied to requests for lipid screening of patients attending the diabetes clinics of Birmingham Heartlands Hospital. The calculated risks for the population were compared with those estimated from the Sheffield tables. Results Of 1060 patients with diabetes mellitus, 215 (20%) had an annual CHD risk greater than or equal to 3%, which is considered to he the threshold at which lipid-lowering drugs are cost-effective. Only 24 of these 215 patients (11%) were correctly identified by the Sheffield tables, which we conclude have an unacceptably low sensitivity in diabetes mellitus. Conclusions A laboratory-based CHD risk calculation system is a practical alternative to the Sheffield system and may have a greater sensitivity in the diabetic clinic.