Differences in accuracy of height, weight, and body mass index between self-reported and measured using the 2018 Korea Community Health Survey data

OBJECTIVES: This study aimed to determine an effective survey method for the accurate calculation of obesity prevalence by comparing the self-reported and measured height, weight, and body mass index (BMI) using the 2018 Korea Community Healthy Survey (CHS) data. METHODS: Raw data from the 2018 CHS were used to analyze the differences, correlation, and agreement between self-reported and measured height, weight, and BMI. RESULTS: The self-reported height was over-reported than the measured height (0.59 cm greater for men and 0.71 cm greater for women), while the self-reported weight was under-reported than the measured weight (0.55 kg less for men and 0.67 kg less for women). Subsequently, the self-reported BMI was under-estimated (0.35 kg/m2 lower for men and 0.49 kg/m2 lower for women) compared with the measured BMI. The kappa statistic and agreement between measured and self-reported values per BMI category (underweight, normal, overweight, and obesity) were 0.82 and 79.6%, respectively. CONCLUSIONS: The prevalence of obesity should be calculated using the measured values provided in the CHS in order to promote local health projects based on accurate evidence.