External validation of two diabetes risk scores in a young UK South Asian population.
OBJECTIVE
To externally validate the Leicester Practice Risk Score (LPRS) and the Leicester Risk Assessment score (LRAS) in a young South Asian population.


METHODS
South Asian participants aged 25-39 years inclusive from a population based screening study were included. The risk scores were calculated and compared to the diagnosis of type 2 diabetes mellitus (T2DM) or T2DM and Impaired Glucose Regulation (IGR, including IFG and IGT) using either an oral glucose tolerance test (OGTT) or a HbA1c (≤48mmol/mol/6.5% and ≤42mmol/mol/6.0% respectively). Measures of discrimination and calibration were calculated.


RESULTS
Of the 331 participants 8 (2.4%) had undiagnosed T2DM and 30 (9.1%) had IGR using an OGTT, 11 (3.4%) and 39 (12.1%) were found using HbA1c. Using the LPRS to detect T2DM on an OGTT gives an area under the ROC curve of 0.91 (95% CI 0.86, 0.97), including those with IGR gives an ROC of 0.72 (0.62-0.81), these values are 0.93 (0.88, 0.98) and 0.68 (0.60, 0.77) when using an HbA1c to define outcome. Acceptable levels of calibration were seen. Similar results are found for the LRAS.


CONCLUSIONS
These scores can be used to identify those with undiagnosed T2DM and/or IGR in a young South Asian population. This is the first study to externally validate scores developed for prevalent undiagnosed disease in this age group using both OGTT and HbA1c.
University of Leicester, Department of Health Sciences, Leicester, UK. Electronic address: lg48@le.ac.uk.
L J
LJ
Gray
University of Leicester, Diabetes Research Centre, Leicester Diabetes Centre, Leicester, UK.
K
K
Khunti
University of Leicester, Diabetes Research Centre, Leicester Diabetes Centre, Leicester, UK.
E G
EG
Wilmot
University of Leicester, Diabetes Research Centre, Leicester Diabetes Centre, Leicester, UK.
T
T
Yates
University of Leicester, Diabetes Research Centre, Leicester Diabetes Centre, Leicester, UK.
M J
MJ
Davies
D000328:Adult; D000368:Aged; D044466:Asian People; D001786:Blood Glucose / Q000032:analysis*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D005260:Female; D018149:Glucose Intolerance; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology
D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
Early detection; Risk scores; Screening; Type 2 diabetes