Accuracy of self-reported weight, height and BMI in US firefighters

Occup Med (Lond). 2014 Jun;64(4):246-54. doi: 10.1093/occmed/kqu040. Epub 2014 Apr 6.


Background: Obesity is of increasing concern especially among firefighters. Bias in self-reported body weight, height and body mass index (BMI) has received a great deal of attention given its importance in epidemiological field research on obesity.

Aims: To determine the validity of self-reported weight, height and BMI and identify potential sources of bias in a national sample of US firefighters.

Methods: Self-reported and measured weight and height (and BMI derived from them) were assessed in a national sample of 1001 career male firefighters in the USA and errors in self-reported data were determined.

Results: There were 1001 participants. Self-reported weight, height and BMI were significantly correlated with their respective measured counterparts, i.e. measured weight (r = 0.990; P < 0.001), height (r = 0.961; P < 0.001) and BMI (r = 0.976; P < 0.001). The overall mean difference and standard deviation between self-reported weight, height and BMI were 1.3±2.0kg, 0.94±1.9cm and 0.09±0.9kg/m(2), respectively, for male firefighters. BMI-based weight status (P < 0.001) was the most consistent factor associated with bias in self-reported BMI, weight and height, with heavier firefighters more likely to underestimate their weight and overestimate their height, resulting in underestimated BMIs. Therefore, using self-reported BMI would have resulted in overestimating the prevalence of obesity (BMI ≥ 30.0) by 1.8%, but underestimating the prevalence of more serious levels of obesity (Class II and III) by 1.2%.

Conclusions: Self-reported weight and height (and the resulting BMI) were highly correlated with measured values. A primary and consistent source of error in self-reported weight, height and BMI based on those indices was BMI-based weight status.

Keywords: Anthropometry; firefighter; fitness; obesity..

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Adult
  • Bias
  • Body Height*
  • Body Mass Index*
  • Body Weight*
  • Firefighters*
  • Humans
  • Male
  • Middle Aged
  • Obesity* / epidemiology
  • Prevalence
  • Reproducibility of Results
  • Self Report*
  • Sex Factors
  • Size Perception*
  • Surveys and Questionnaires
  • United States
  • Young Adult