Conclusions HbA1c is neither sensitive nor specific for detecting pre‐diabetes ; fasting glucose is specific but not sensitive .
Interventions in people classified through screening as having pre‐diabetes have some efficacy in preventing or delaying onset of type 2 diabetes in trial population s. As screening is inaccurate , many people will receives an incorrect diagnosis and be referred on for interventions while others will be falsely reassured and not offered the intervention .
These findings suggest that “ screen and treat ” policies alone are unlikely to have substantial impact on the worsening epidemic of type 2 diabetes .
& NA ; Objectives To assess diagnostic accuracy of screening tests for  pre‐diabetes  and efficacy of interventions ( lifestyle or metformin ) in preventing onset of type 2 diabetes in people with pre‐diabetes .
Sensitivity and specificity of glycated hemoglobin as a diagnostic test for diabetes and prediabetes in Arabs.
CONTEXT Glycated hemoglobin ( A1C ) has been recommended by the American Diabetes Association for the diagnosis of diabetes and prediabetes . The diagnostic utility of A1C has not been evaluated in Arabs , a population at increased risk for developing diabetes . OBJECTIVE Our objective was to examine the sensitivity and specificity of A1C for the diagnosis of diabetes and prediabetes in Arabs . DESIGN & SETTING In this cross-sectional study , glucose tolerance was classified by the American Diabetes Association diagnostic criteria specified for A1C , fasting plasma glucose , and 75-g oral glucose tolerance test . PARTICIPANTS A population -based representative sample of 482 r and omly selected adult Arabs without known diabetes was studied . MAIN OUTCOME MEASURES Sensitivity , specificity , and area under the receiver operating characteristic curve of A1C diagnostic cutpoints for diabetes and prediabetes were calculated . κ Coefficients were used to test for agreement between A1C categorization and glucose-based diagnoses . RESULTS A1C testing correctly identified 5 % of individuals diagnosed with diabetes by oral glucose tolerance test , 13 % by fasting plasma glucose , and 41 % by both criteria . A1C alone identified 14 % of individuals diagnosed with impaired glucose tolerance , 9 % with impaired fasting glucose , and 33 % with both abnormalities . Sensitivity , specificity , and area under the receiver operating characteristic curve were 19 % ( 16 - 23 % ) , 100 % ( 99 - 100 % ) , and 77 % ( 69 - 85 % ) for diabetes A1C cutpoint and 14 % ( 11 - 17 % ) , 91 % ( 89 - 94 % ) , and 57 % ( 52 - 62 % ) for prediabetes A1C range . A1C cutpoint of 6.2 % for diabetes and 5.1 % for prediabetes yielded the highest accuracy but still missed 73 % of those with diabetes and 31 % with prediabetes . Agreement between A1C and diabetes ( κ = 0.2835 ) or prediabetes ( κ = 0.0530 ) was low . CONCLUSIONS A1C-based criteria yield a high proportion of false-negative tests for diabetes and prediabetes in Arabs . SUMMARY Racial/ethnic differences in A1C performance for diagnosis and prediction of diabetes exist . This paper examines its utility against glucose measurements in an at-risk Arab population
Conclusions HbA1c is neither sensitive nor specific for detecting pre‐diabetes ; fasting glucose is specific but not sensitive .
Interventions in people classified through screening as having pre‐diabetes have some efficacy in preventing or delaying onset of type 2 diabetes in trial population s. As screening is inaccurate , many people will receives an incorrect diagnosis and be referred on for interventions while others will be falsely reassured and not offered the intervention .
These findings suggest that “ screen and treat ” policies alone are unlikely to have substantial impact on the worsening epidemic of type 2 diabetes .
& NA ; Objectives To assess diagnostic accuracy of screening tests for  pre‐diabetes  and efficacy of interventions ( lifestyle or metformin ) in preventing onset of type 2 diabetes in people with pre‐diabetes .