Development and Validation of a Risk Score for Diabetes Screening in Oman
Objective: To develop and validate a diabetic risk score model, as a non-invasive and selfadministered screening tool, to be used in the general Omani population. Methods: The World Health Survey (WHS) 2008 data from Oman (n=2,720) was used to develop the risk score model. Multivariable logistic regression with backward stepwise method was implemented to obtain risk factors regression coefficients for gender, age, educational attainment, marital status, place of residence, hypertension, body mass index, waist circumference, tobacco use, daily fruits and vegetables intake and weekly physical activity. The model coefficients were multiplied by a factor of five to allocate each variable category a risk score. The total score was calculated as the sum of these individual scores. The score was validated using another Omani cohort (Sur Survey 2006 dataset, n=1,355) Page 2 of 24 by calculating the area under the receiver-operating characteristic (ROC) curve (AUC) and optimal score sensitivity and specificity were determined. Results: A robust diabetes risk score model was produced, which composed of eight variables (age, gender, education level, marital status, place of residence, hypertension, smoking status and body mass index) with an optimal cutoff point of ≥15 to classify persons with possible prevalent T2DM. At this cutoff point, the model had a sensitivity of 71.1%, specificity of 74.4% and AUC of 0.80 (95% CI) 0.7–0.82, when internally validated (in the WHS 2008 cohort). When the model was externally validated (using the Sur 2006 cohort), the optimal cutoff point for the score was ≥13, with a lower sensitivity (54%), higher specificity (79%) and an AUC of 0.74 (95% CI 0.70–0.78). In contrast, test of the old Omani, Kuwaiti, Saudi and Finnish diabetes risk scores, in both of our study populations, showed poor performance of these models among Omanis with poor sensitivity (29% to 63.5%) and reasonable specificity (70% to 80%). Conclusion: The developed diabetes risk score for screening prevalent T2DM, provides an easy-to-use self-administered tool to identify most individuals at risk of this condition in Oman. The score incorporates eight diabetes-associated risk factors that can also act as a tool to increase people’s awareness about the importance of diabetes-related risk factors and provide information for policy makers to establish a diabetes prevention programs.