(HealthDay)—Many children are eligible for type 2 diabetes screening, but few test positive for prediabetes or diabetes, according to a study published online Aug. 10 in Pediatrics.

Amelia S. Wallace, from the Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues conducted a involving 14,119 youth aged 10 to 19 years in the 1999 to 2016 National Health and Nutrition Examination Survey. The authors evaluated the performance of the American Diabetes Association risk-based screening criteria, as well as the performance of current clinical definitions of prediabetes and diabetes based on hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) for identifying high cardiometabolic risk.

The researchers found that 25.5 percent of U.S. youth were eligible for screening. The and specificity of the screening criteria for detecting any hyperglycemia were low for HbA1c ≥5.7 percent (55.5 and 76.3 percent, respectively) and FPG ≥100 mg/dL (35.8 and 77.1 percent, respectively). Confirmed undiagnosed diabetes was seen rarely (<0.5 percent of youth). More than 85 percent of diabetes cases were diagnosed. Consistently stronger and more specific associations with cardiometabolic risk were seen for HbA1c-defined hyperglycemia (specificity, 98.6 percent; sensitivity, 4.0 percent) than with FPG-defined hyperglycemia (specificity, 90.1 percent; sensitivity, 19.4 percent).

"The current screening approach targets a large number of children and adolescents, whereas few will test positive for diabetes or prediabetes, and a substantial number of children with hyperglycemia may be missed," the authors write.