1515-P: Thai Diabetes Risk Score Performed Less Well in Predicting Incident Diabetes in a General Population: External Validation in the HCUR Cohort

Background: An existing Thai diabetes risk score was developed using data from a worker cohort and has been advocated as a tool to predict diabetes risk in a Thai population. However, the risk score has not been validated in an external cohort, so its accuracy in risk prediction remained uncertain. Aim: To validate the Thai diabetes risk score in an external cohort of Thai general population in the Health Checks Ubon Ratchathani (HCUR) cohort.

Methods: The Thai diabetes risk score was externally validated against incident cases of diabetes developed over 6 years in a cohort of 332,038 individuals aged >=30 years free of clinically and/or biochemically diagnosed diabetes. Published coefficients for the Thai diabetes risk score were used to compute risk score for each individual. Incident diabetes was defined as physician diagnosed diabetes. We computed standard measures of predictive ability including discriminatory ability measured by the area under the receiver operating characteristic curves (aROC) and calibration, as well as the sensitivity, specificity, positive/negative predictive values, and false negative for cut-off points indicating high risk groups.

Results: Over a 6-year period between 2007 and 2012, 7,372 new cases of diabetes developed (an incidence of 2.2%). The Thai risk score showed low discriminative ability and was poorly calibrated for predicting diabetes, with the aROC of 0.574 (95% CI 0.567 - 0.581) and Hosmer-Lemeshow chi-square statistic of 70.04 (p<0.001). A cut-off point for very high risk group (risk score>=8) had low sensitivity and high specificity (18% and 90% respectively), albeit a satisfactorily low false negative of 2%.

Discussion: The current Thai diabetes risk score performed poorly in predicting incident diabetes in a general population and hence requires re-calibration.