Truth be told: evidence of wheelchair users' accuracy in reporting their height and weight

Abstract

Objectives: To examine whether wheelchair users' self-reports of height and weight differed significantly from direct measurements and whether weight category classifications differed substantially when based on self-reported or measured values.

Design: Single group, cross-sectional analysis. Analyses included paired t tests, chi-square test, analysis of variance, and Bland-Altman agreement analyses.

Setting: A university-based exercise lab.

Participants: Community-dwelling wheelchair users (N=125).

Interventions: Not applicable.

Main outcome measure: Participants' self-reported and measured height, weight, and body mass index.

Results: Paired t tests revealed that there were significant differences between wheelchair users' self-reported and measured values for height (difference of 3.1±7.6cm [1.2±3.0in]), weight (-1.7±6.5kg [-3.6±14.2lb]), and BMI (-1.6±3.3). These discrepancies also led to substantial misclassification into weight categories, with reliance on self-reported BMI underestimating the weight status of 20% of the sample.

Conclusions: Our findings suggest that similar to the general population, wheelchair users are prone to errors when reporting their height and weight and that these errors may exceed those noted in the general population.

Trial registration: ClinicalTrials.gov NCT00866112.