Statistical comparison of the external validity (positive predictive value and negative predictive value) of three anthropometric indices used in the diagnosis of pathological nutritional situations overweight and obesity
Keywords:External validity, anthropometric indices, overweight and obesity
To compare the external validity (positive predictive value and negative predictive value) of the Body Mass Index versus the external validity of the Waist/Hip Index versus the external validity of the Abdominal Circumference as diagnostic methods indicating overweight and obesity in adult patients aged 18–64 years of age of both genders who attended the Integral Hospital "Jose Maria Morelos" of the Mayan municipality of Jose Maria Morelos, Quintana Roo, Mexico, in the period from August 1, 2017 to July 31, 2018. The study design corresponds to that of a descriptive observational epidemiological study without directionality and with prospective temporality. The study was carried out in a population consisting of 300 adult patients [119 (39.67%) of the male gender and 181 (60.33%) of the female gender]. The Miller et al. Equation, which provides the ideal body weight for both genders, was used as a reference test or Gold Standard. Using this equation, 171 (57.00%) and 129 (43.00%) observation units were labeled with and without overweight and obesity, respectively. In ascending numerical order, the observed positive predictive values were 68.32% (138/202) for Abdominal Circumference; 69.49% (123/177) for the Waist/Hip Ratio; and 70.85% (141/199) for the Body Mass Index. Regarding the negative predictive values observed, in ascending numerical order, they were 60.98% (75/123) for the Waist/Hip Index; 66.33% (65/98) for the Abdominal Circumference; and 70.30% (71/101) for the Body Mass Index. The diagnostic test with the highest positive predictive value and the highest negative predictive value was the Body Mass Index.