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.

Spanish Version of the System Usability Scale for the Assessment of Electronic Tools: Development and Validation.

BACKGROUND: The System Usability Scale (SUS) is a common metric used to assess the usability of a system, and it was initially developed in English. The implementation of electronic systems for clinical counseling (eHealth and mobile health) is increasing worldwide. Therefore, tools are needed to evaluate these applications in the languages and regional contexts in which the electronic tools are developed. OBJECTIVE: This study aims to translate, culturally adapt, and validate the original English version of the SUS into a Spanish version. METHODS: The translation process included forward and backward translation. Forward translations were made by 2 native Spanish speakers who spoke English as their second language, and a backward translation was made by a native English speaker. The Spanish SUS questionnaire was validated by 10 experts in mobile app development. The face validity of the questionnaire was tested with 10 mobile phone users, and the reliability testing was conducted among 88 electronic application users. RESULTS: The content validity index of the new Spanish SUS was good, as indicated by a rating of 0.92 for the relevance of the items. The questionnaire was easy to understand, based on a face validity index of 0.94. The Cronbach α was .812 (95% CI 0.748-0.866; P<.001). CONCLUSIONS: The new Spanish SUS questionnaire is a valid and reliable tool to assess the usability of electronic tools among Spanish-speaking users.

Design of a cluster-randomized trial of the effectiveness and cost-effectiveness of metformin on prevention of type 2 diabetes among prediabetic Mexican adults (the PRuDENTE initiative of Mexico City).

INTRODUCTION: Type 2 diabetes (T2D) is a global epidemic, and nations are struggling to implement effective healthcare strategies to reduce the burden. While efficacy studies demonstrate that metformin can reduce incident T2D by half among younger, obese adults with prediabetes, its real-world effectiveness are understudied, and its use for T2D prevention in primary care is low. We describe the design of a pragmatic trial to evaluate the incremental effectiveness of metformin, as an adjunct to a simple lifestyle counseling. METHODS: The "Prevención de la Diabetes con Ejercicio, Nutrición y Tratamiento" [Diabetes Prevention with Exercise, Nutrition and Treatment; PRuDENTE, (Spanish acronym)] is a cluster-randomized trial in Mexico City's public primary healthcare system. The study randomly assigns 51 clinics to deliver one of two interventions for 36 months: 1) lifestyle only; 2) lifestyle plus metformin, to 3060 patients ages 30-65 with impaired fasting glucose and obesity. The primary endpoint is incident T2D (fasting glucose ≥126 mg/dL, or HbA1c ≥6.5%). We will also measure a range of implementation-related process outcomes at the clinic-, clinician- and patient-levels to inform interpretations of effectiveness and enable efforts to refine, adapt, adopt and disseminate the model. We will also estimate the cost-effectiveness of metformin as an adjunct to lifestyle counseling in Mexico. DISCUSSION: Findings from this pragmatic trial will generate new translational knowledge in Mexico and beyond, both with respect to metformin's real-world effectiveness among an 'at-risk' population, and uncovering facilitators and barriers to the reach, adoption and implementation of metformin preventive therapy in public primary care settings. TRIAL REGISTRATION: This trial is registered at Clinicaltrials.gov (NCT03194009).