Screening for diabetes in general practice: cross sectional population study.

OBJECTIVE

To assess the policy proposed by the American Diabetes Association of universal screening in general practice of all patients aged over 45 years for diabetes.

DESIGN

Cross sectional population study.

SETTING

Local general practice in the United Kingdom.

PARTICIPANTS

All patients aged over 45 not known to have diabetes.

MAIN OUTCOME MEASURES

Prevalence of diabetes in the screened population, cardiovascular risk profile of patients diagnosed as having diabetes after screening.

RESULTS

Of 2481 patients aged over 45 and not known to have diabetes, 876 attended for screening. There were no significant demographic differences between the screened and unscreened patients. Prevalence of diabetes in patients with age as a sole risk factor was 0.2% (95% confidence interval 0% to 1.4%). Prevalence of diabetes in patients with age and one or more other risk factors (hypertension, obesity, or a family history of diabetes) was 2.8% (1.6% to 4.7%). Four hours a week for a year would be needed to screen all people over 45 in the practice's population; about half this time would be needed to screen patients with risk factors other than age. More than 80% of patients newly diagnosed as having diabetes had a 10 year risk of coronary heart disease >15%, 73% (45% to 92%) were hypertensive, and 73% (45% to 92%) had a cholesterol concentration >5 mmol/l.

CONCLUSIONS

Screening for diabetes in general practice by measuring fasting blood glucose is feasible but has a very low yield in patients whose sole risk factor for diabetes is age over 45. Screening in a low risk population would best be targeted at patients with multiple risk factors.