Validity of Self-Reported Body Mass Index and Sleeping Problems Among Adult Population of Georgia

ABSTRACT

Purpose: This study assessed the validity of body mass index (BMI) derived from self-reported height and weight in comparison to BMI derived from clinical measurement. We further examined the misclassification effect of self-reported BMI in association with complaints of snoring and excessive daytime sleepiness.

Methods: Data came from a population-based study of chronic fatigue syndrome (CFS) and unwellness, between September 2004 and July 2005, in metropolitan, urban, and rural Georgia. We compared self-reported with clinicallymeasured height and weight from 774 persons aged 18-59 and the bias impact on their association with snoring and excessive daytime sleepiness.

Results: The correlation coefficient between self-reported and clinically-measured BMI was 0.92 (p<0.0001) and intraclass correlation coefficient was 0.90. For overweight persons (BMI >=25 kg/m2), self-reported BMI had 89% sensitivity and 95% specificity compared to clinically-measured BMI. Misclassification of self-reported BMI categories revealed slightly higher odds ratios (ORs) for obese categories in predicting the likelihood of having a snoring problem than those based on measured values.

Conclusions: Self-reported height and weight are valid for determining BMI categories and the relationship to snoring in a large-scale population study.