The usefulness of screening for diabetes mellitus among persons without clinically detectable disease is controversial. Clearly, treating patients with clinically detectable disease can decrease complications, but there is no evidence of benefit from earlier treatment initated after detection by screening. Recent studies showing the benefit of reducing the risk of cardiovascular disease (CVD) in diabetic patients have reopened the question of screening for diabetes. Hoerger and associates performed a cost-benefit analysis comparing universal diabetes screening and screening targeted to patients with hypertension.

A model of five types of potential complications was developed using mathematical models of diabetes progression to simulate lifetime health care costs and quality-adjusted life years, in addition to demographic information about patients with diabetes and CVD risk comorbidities, such as hypertension, smoking, and high cholesterol levels. The complication paths included nephropathy, neuropathy, coronary heart disease (CHD), retinopathy, and stroke. Screening was incorporated into the model, with some patients identified earlier and slowly progressing toward complications.

Screening identifies diabetes earlier and delays progression to complications, but it has some financial cost. Routine screening was assumed to diagnose diabetes five years before usual clinical diagnosis (five years after onset rather than 10 in the absence of screening). Patients who screened positive were assumed to receive aggressive diabetes treatment and more aggressive standard hypertensive treatment if they had high blood pressure. Another calculation was made for targeted screening, in which only persons with hypertension would be screened for diabetes. The cost of screening (including laboratory and physician costs) was found to be $24.40. Positive tests were assumed to be repeated to make a definitive diagnosis. Costs of intensive diabetes and hypertension treatment were included in the analysis.

Compared with no screening at all ages, results for targeted screening showed greater cost-effectiveness than universal screening. In patients older than 55 years who are at greater risk for CHD events, both universal and targeted screenings are more cost effective than no screening. The most cost-effective approach to one-time diabetes screening is to target hypertensive persons between the ages of 55 and 75.

The authors conclude that targeted diabetes screening in hypertensive patients older than 55 years is the most efficient strategy. This targeted screening would provide most of the benefit of universal screening at significantly reduced cost.

In an editorial in the same journal, Nathan and Herman point out the importance of trying to uncover diabetes during the nine- to 12-year early asymptomatic period because of the possibility of decreasing complications that begin to develop during the prediabetic phase. They note that models are dependent on prevailing treatment pathways, which may be suboptimal in persons with diabetes, and that improved complication risk reduction in this population may increase the value of early screening in larger populations.