Obesity prevalence and accuracy of BMI-defined obesity in Russian firefighters

Background No data exist on obesity or the accuracy of body mass index (BMI) in Russian Federation firefighters. Aims To determine the prevalence of obesity and rates of misclassification of BMI-based obesity status. Methods Career firefighters in the Moscow region completed anthropometric assessments including height, weight, BMI, body fat per cent (BF%) and waist circumference (WC). Using these three methods, we defined obesity as BMI ≥30, BF% >25 and WC >102, respectively. Results The study group consisted of 167 male firefighters. Obesity prevalence was 22% for BMI [95% confidence interval (CI) 16.9-28.5], 60% for BF% (95% CI 52.5-67.3) and 28% for WC (95% CI 21.3-34.9). False positive rates for BMI-based obesity status were low, with 3% (95% CI -1.1 to 7.1) and 6% (95% CI 1.6-9.9) of non-obese participants defined by BF% and WC standards misidentified as obese using BMI. However, 65% (95% CI 55.7-77.4) of BF%-defined obese participants and 36% (95% CI 22.5-49.9) of WC-defined obese participants were misclassified as non-obese using BMI (i.e. false negatives). Conclusions Rates of BMI-based obesity in Russian male firefighters were similar to that of males in the general Russian adult male population. Compared with BF% or WC standards, BMI-based obesity classi- fication produced low rates of false positives but demonstrated high rates of false negatives.