Developing equations to predict waist circumference measurements based on the National Heart, Lung, and Blood Institute method from the World Health Organization method.

ABSTRACT

PURPOSE: The purpose of the study was to convert waist circumference (WC) measurements obtained by the World Health Organization (WHO-WC) method to the National Heart, Lung, and Blood Institute (NHLBI-WC) method. METHODS: During 2016, the National Health and Nutrition Examination Survey participants aged 20 years and older had two different WC measurements taken (n = 2405). The mean differences in the WC between the NHLBI-WC and WHO-WC measurements were calculated. Multivariable prediction models were developed to predict the NHLBI-WC from the measured WHO-WC. Sensitivity and specificity of the abdominal obesity classification (AOC) were calculated for the measured WHO-WC and the predicted NHLBI-WC. Kappa coefficients were calculated to evaluate the agreements between the AOC derived from the NHLBI-WC and from the WHO-WC and the predicted NHLBI-WC. RESULTS: The mean differences between the NHLBI-WC and WHO-WC were 0.8 cm for males and 3.2 cm for females (P ≤ .05). Sensitivity of the AOC for the measured WHO-WC was 93% for males and 87% for females, and the specificity of the AOC was 97% or greater for both genders. Sensitivity and specificity of the AOC for the predicted NHLBI-WC were 95% or greater for both genders. The AOC derived from the predicted NHLBI-WC had higher agreements for both genders. CONCLUSIONS: The prediction equations provided may be used to predict the NHLBI-WC from the WHO-WC for comparability in WC estimates across studies.