Screening for Diabetes and Prediabetes Should Be Cost-Saving in Patients at High Risk

Abstract

OBJECTIVE: Although screening for diabetes and prediabetes is recommended, it is not clear how best or whom to screen. We therefore compared the economics of screening according to baseline risk. RESEARCH DESIGN AND METHODS: Five screening tests were performed in 1,573 adults without known diabetes—random plasma/capillary glucose, plasma/capillary glucose 1 h after 50-g oral glucose (any time, without previous fast, plasma glucose 1 h after a 50-g oral glucose challenge [GCTpl]/capillary glucose 1 h after a 50-g oral glucose challenge [GCTcap]), and A1C—and a definitive 75-g oral glucose tolerance test. Costs of screening included the following: costs of testing (screen plus oral glucose tolerance test, if screen is positive); costs for false-negative results; and costs of treatment of true-positive results with metformin, all over the course of 3 years. We compared costs for no screening, screening everyone for diabetes or high-risk prediabetes, and screening those with risk factors based on age, BMI, blood pressure, waist circumference, lipids, or family history of diabetes. RESULTS: Compared with no screening, cost-savings would be obtained largely from screening those at higher risk, including those with BMI >35 kg/m2, systolic blood pressure ≥130 mmHg, or age >55 years, with differences of up to −46% of health system costs for screening for diabetes and −21% for screening for dysglycemia110, respectively (all P < 0.01). GCTpl would be the least expensive screening test for most high-risk groups for this population over the course of 3 years. CONCLUSIONS: From a health economics perspective, screening for diabetes and high-risk prediabetes should target patients at higher risk, particularly those with BMI >35 kg/m2, systolic blood pressure ≥130 mmHg, or age >55 years, for whom screening can be most cost-saving. GCTpl is generally the least expensive test in high-risk groups and should be considered for routine use as an opportunistic screen in these groups.