Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes Among U.S. Adults

Devin M. Mann; April P. Carson; Daichi Shimbo; Vivian Fonseca; Caroline S. Fox; Paul Muntner

Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes Among U.S. Adults
Mann, Devin M.
Carson, April P.
Shimbo, Daichi
Fonseca, Vivian
Fox, Caroline S.
Muntner, Paul
Center for Behavioral Cardiovascular Health
Persistent URL:
Book/Journal Title:
Diabetes Care
American Diabetes Association
OBJECTIVE New clinical practice recommendations include A1C as an alternative to fasting glucose as a diagnostic test for identifying pre-diabetes. The impact of these new recommendations on the diagnosis of pre-diabetes is unknown. RESEARCH DESIGN AND METHODS Data from the National Health and Nutrition Examination Survey 1999–2006 (n = 7,029) were analyzed to determine the percentage and number of U.S. adults without diabetes classified as having pre-diabetes by the elevated A1C (5.7–6.4%) and by the impaired fasting glucose (IFG) (fasting glucose 100–125 mg/dl) criterion separately. Test characteristics (sensitivity, specificity, and positive and negative predictive values) using IFG as the reference standard were calculated. RESULTS The prevalence of pre-diabetes among U.S. adults was 12.6% by the A1C criterion and 28.2% by the fasting glucose criterion. Only 7.7% of U.S. adults, reflecting 61 and 27% of those with pre-diabetes by A1C and fasting glucose, respectively, had pre-diabetes according to both definitions. A1C used alone would reclassify 37.6 million Americans with IFG to not having pre-diabetes and 8.9 million without IFG to having pre-diabetes (46.5 million reclassified). Using IFG as the reference standard, pre-diabetes by the A1C criterion has 27% sensitivity, 93% specificity, 61% positive predictive value, and 77% negative predictive value. CONCLUSIONS Using A1C as the pre-diabetes criterion would reclassify the pre-diabetes diagnosis of nearly 50 million Americans. It is imperative that clinicians and health systems understand the differences and similarities in using A1C or IFG in diagnosis of pre-diabetes.
Prediabetic state
Medical sciences
Publisher DOI:
Item views
text | xml
Suggested Citation:
Devin M. Mann, April P. Carson, Daichi Shimbo, Vivian Fonseca, Caroline S. Fox, Paul Muntner, , Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes Among U.S. Adults, Columbia University Academic Commons, .

Columbia University Libraries | Policies | FAQ