Measuring height without a stadiometer: Empirical investigation of four height estimates among wheelchair users

Objectives: To compare whether four methods to measure or estimate height among those who cannot stand result in significantly different estimates and to determine which method derives the best estimate. Methods: Height data were obtained for 123 wheelchair users. Height estimates included asking for self-report and measuring recumbent length, knee height, and armspan. All analyses were conducted separately for men and women. Repeated measures ANOVAs determined whether there were significant differences across the four height estimates and BMI values using these estimates. A two-group confirmatory factor analysis assessed which measure provided the best estimate of height in this population. Results: The four measures yielded significantly different height estimates and BMI values for both men and women. For both genders, armspan resulted in the longest estimate and measured recumbent length the shortest, with the reverse pattern for BMI values. CFA findings indicated that the common variance estimates were outstanding for recumbent length (>90%) and knee height (>80%) and very good for self-report (>74%), while the common variance for armspan was poor (<44%). Conclusions: The measurement method used to estimate height yields significantly different values for both height and BMI among wheelchair users who cannot stand to be measured using a stadiometer. These results suggest that measuring knee height to include in an equation to estimate height may be the most valid method for this population. Using a valid and relatively easy measurement method can facilitate improved weight status surveillance and health care delivery for wheelchair users.