Diagnostic performance of questionnaires to identify individuals with impaired fasting glucose in Mexican adult population.

Aims: To evaluate the diagnostic performance of five questionnaires to identify impaired fasting glucose (IFG) in Mexican adult population.

Methods: The study included 23,311 subjects from five cohorts, three composed of individuals who sought medical advice in their first level clinics or participated in research studies and two representative surveys of the Mexican population. The reference standard was IFG which was defined as a fasting glucose ≥ 100 mg/dL. Diagnostic performance was evaluated with specificity, sensitivity, positive and negative predictive values, area under the curve, and the proportion of correctly classified individuals.

Results: The prevalence of IFG ranged from 14.4 to 48.1 % across the cohorts. Diagnostic performance of the questionnaires varied in each cohort depending on IFG prevalence. The questionnaires designed by Rojas, American Diabetes Association and International Diabetes Federation had the best performance considering the correct classification (>66.0 %) of subjects in all cohorts. However, Rojas' questionnaire had the best balance between sensitivity and specificity across the cohorts.

Conclusion: In the Mexican population, considering different scenarios, the Rojas' questionnaire had the best diagnostic performance. The implementation of questionnaires for the identification of prediabetes and undiagnosed diabetes requires further study in specific populations.