Purpose: To evaluate the effectiveness and cost-effectiveness of four screening strategies for identifying overweight and obese adolescents with dysglycemia (prediabetes or diabetes) from a single-payer and societal perspective.
Method: We assumed that 2.5 million US children qualify for screening, with a 15% prevalence of dysglycemia(n=375,000 children). Test performance was based on a clinical study of nonfasting test performance. We calculated direct costs (testing costs) using Medicare reimbursement rates, and indirect costs (patient time costs) using data from the Bureau of Labor Statistics. Costs were expressed in $US2010. The 4 strategies considered included: (1)2-hour oral glucose tolerance test (2-hr OGTT)(positive greater than or equal to 140 mg/dl) only, or nonfasting initial screening tests [(2)HbA1c greater than or equal to 5.7%); (3)random glucose(positive greater than or equal to 100 mg/dl); or (4)1-hour glucose tolerance test(1-hr OGTT) (positive greater than or equal to 110 mg/dl)], followed by a 2-hr OGTT only if the initial test is positive. Outcomes included the proportion of cases identified, total screening costs, and cost per case identified. We also conducted sensitivity analyses assuming a 50% lower adherence for the 2-hr OGTT only strategy, and increases or decreases in the prevalence of dysglycemia(±25%).
Result: Compared with the other strategies, HbA1c was associated with a lower number of true positives, a higher number of missed cases, and higher total costs and a higher cost per case detected (direct and direct combined with indirect). This is highlighted in the figure which shows the "efficiency frontier", plotting effectiveness (% of cases of dysglycemia missed) against efficiency (cost per case). An ideal test is located near the origin. Although the 2-hr OGTT only strategy had high effectiveness and a lower cost per case identified, when we assumed only 50% adherence, screening effectiveness dropped to 50% with lower overall costs, but the same cost per case identified. At higher and lower estimates of prevalence, test effectiveness and overall costs did not change, but the cost per case increased or decreased by 25%.
Conclusion: HbA1c was an inferior test compared with the other test strategies. 1-hr OGTT and random glucose were intermediate regarding efficiency and effectiveness, and therefore may be viable strategies for dysglycemia screening in adolescents.