Evaluation of Agreement of Overweight Screening Criteria in Adolescents: Korean National Health and Nutrition Examination Surveys

Background: The increasing prevalence of overweight children and childhood obesity has led to early development of obesity-related diseases, including diabetes. Screening tests for type 2 diabetes in children indicate overweight as a major risk factor. Three overweight screening criteria have been considered: body mass index (BMI) >85th percentile (overweight 1, OW1), weight for height >85th percentile (OW2), and weight >120% of ideal for height (OW3). This study was conducted to evaluate the agreement in these screening criteria and the impact of increased use of screening methods. Methods: Data were obtained from 965 Korean adolescents (521 boys and 444 girls). The subjects were classified into overweight and normal weight groups by the three above criteria. The agreement between criteria was evaluated using Cohen's kappa value. Furthermore, we studied the relationships between the criteria and parameters of height, weight, BMI, and z score, based on the 2007 Korean growth chart. Results: Totals of 188, 139, and 115 adolescents were classified as OW1, OW2, and OW3, respectively.The kappa values were 0.798, 0.710, and 0.891 for OW1 and OW2, OW1 and OW3, and OW2 and OW3, respectively. Weight, weight-z, BMI, and BMI-z were greater among subjects in all overweight groups compared to the normal weight group. However, the heights of the subjects did not differ between the three groups. Conclusion: Active assessment of overweight status using OW1 could be improved by including more adolescents and focusing on the variability of individual growth and disease risk, even though substantial agreement was observed among the three overweight screening criteria.