Assessment of the validity of multiple obesity indices compared with obesity-related co-morbidities

Objective The aim of the present study was to compare selected obesity indicators with comprehensive health status. Design The study employed a pooled cross-sectional design. Setting BMI, waist circumference, waist-to-height ratio (WHtR) and body fat percentage were considered as indirect obesity indicators. The Edmonton Obesity Staging System (EOSS) was used as a composite indicator to comprehensively reflect obesity-related co-morbidities. Cohen's kappa coefficient was used to evaluate inter-measurement agreement for obesity. Conformity of indirect obesity indicators to the EOSS was assessed based on percentage agreement (proportion classified as obese and severely unhealthy as a result of obesity among the total sample), sensitivity (proportion classified as obese among individuals severely unhealthy as a result of obesity) and specificity (proportion classified as non-obese among fairly healthy individuals). Logistic regression analysis was used to identify the sociodemographic factors most strongly associated with conformity. Participants The study included 17338 adults from the Korea National Health and Nutrition Examination survey conducted between July 2008 and May 2011. Results Level of conformity to the EOSS was highest for WHtR (60 center dot 77 %) and lowest for BMI (35 center dot 96 %). WHtR and BMI had the highest sensitivity (53 center dot 7 %) and specificity (98 center dot 4 %), respectively. Predictability of conformity was lower among men for all indirect obesity indicators. Conclusions WHtR has the greatest potential to identify individuals at risk of health problems due to obesity. Individual demographic factors must be considered in selecting the most appropriate obesity measurement.