Development and Validation of a Risk Score for Diabetes Screening in Oman.

OBJECTIVES

We sought to develop and validate a diabetic risk score model as a non-invasive and self-administered screening tool to be used in the general Omani population.

METHODS

The 2008 World Health Survey (WHS) data from Oman (n = 2720) was used to develop the risk score model. Multivariable logistic regression with the backward stepwise method was implemented to obtain risk factors regression coefficients for sex, age, educational attainment, marital status, place of residence, hypertension, body mass index (BMI), waist circumference, tobacco use, daily fruit and vegetable 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 = 1355) 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 composed of eight variables (age, sex, education level, marital status, place of residence, hypertension, smoking status, and BMI) with an optimal cutoff point of ≥ 15 to classify persons with possible prevalent type 2 diabetes mellitus (T2DM). At this cutoff point, the model had a sensitivity of 71.1%, specificity of 74.4%, and AUC of 0.80 (95% confidence interval (CI): 0.78-0.82), 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 (54.0%), higher specificity (79.0%), and an AUC of 0.74 (95% CI: 0.70-0.78). In contrast, the test of the old Omani, Kuwaiti, Saudi, and Finnish diabetes risk scores in our study populations showed poor performance of these models among Omanis with poor sensitivity (29% to 63.5%) and reasonable specificity (70% to 80%).

CONCLUSIONS

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 policymakers to establish diabetes prevention programs.