Differences in BMI obesity measures in a workers compensation population: a cross-sectional study

Area of Science:

• Occupational Health
• Biometrics
• Body Composition Analysis

Background:

• Body Mass Index (BMI) is a widely used metric for assessing weight categories.
• However, its accuracy in determining body fat percentage, especially in specific populations, requires validation.
• Dual-energy X-ray absorptiometry (DEXA) offers a more precise measurement of body fat percentage (%BF).

Purpose of the Study:

• To evaluate the accuracy of BMI in assessing body fat percentage compared to DEXA %BF.
• To determine the reliability of BMI as an indicator of obesity within a worker compensation cohort.

Main Methods:

• A 5-year cohort study involving 1394 workers' compensation patients.
• Pearson correlation coefficient was used to assess agreement between BMI and DEXA %BF.
• Sensitivity and specificity analyses were performed to evaluate BMI's ability to identify obesity.

Main Results:

• BMI showed a specificity of 0.658 and sensitivity of 0.735 for identifying obesity (≥30kg/m²).
• Correlation between BMI and DEXA %BF was stronger in females (0.66) than males (0.55).
• Age influenced correlation, with weaker agreement in older individuals (0.42) versus younger ones (0.59).

Conclusions:

• BMI is an unreliable indicator of true obesity in the worker compensation population.
• A significant portion (29.8%) of individuals were reclassified based on DEXA %BF measurements.
• DEXA %BF is recommended for a more accurate body composition assessment in this demographic.