Assessment & Research

Measuring waist circumference in disabled adults.

Waninge et al. (2010) · Research in developmental disabilities 2010
★ The Verdict

Measure waist circumference while the client lies supine, then use the study’s quick equation to get the standing value you need for health charts.

✓ Read this if BCBAs who write health-monitoring protocols for adults with severe or profound ID in residential or day programs.
✗ Skip if Clinicians serving only verbal or ambulatory clients who can stand for a standard tape measure.

01Research in Context

01

What this study did

The team wanted to track waist size in adults who could not stand. Many clients with severe intellectual disability stay in wheelchairs or beds.

They measured each person lying flat. Then they built a short math rule that turns the lying number into the standing number everyone else uses.

02

What they found

Two different staff got almost the same tape-measure read. The new rule predicted the standing waist size within a few centimeters.

The method works for clients with the most severe physical and cognitive limits.

03

How this fits with other research

Amore et al. (2011) did the same kind of check for a sleep questionnaire. Both papers prove you can trust a simple tool after you test it in the ID group first.

Macht (1971) trained kids to press a lever to show how well they see. Jones et al. (2010) did not need a lever, but both studies solve the same problem: how to get a body measure when the client cannot follow the usual steps.

Dudley et al. (2019) found that staff rate QOL lower for people with more severe ID. That warning matters here too—always measure the waist yourself instead of guessing.

04

Why it matters

You can now add waist circumference to annual health screens without moving the client out of bed. Plot the converted value on standard charts to spot weight gain early and show the doctor clear numbers.

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→ Action — try this Monday

Add one supine waist measure to your next annual assessment and compare the converted number to last year’s standing estimate.

02At a glance

Intervention
not applicable
Design
other
Sample size
203
Population
intellectual disability
Finding
positive
Magnitude
large

03Original abstract

To date, it is unknown whether waist circumference can be measured validly and reliably when a subject is in a supine position. This issue is relevant when international standards for healthy participants are applied to persons with severe intellectual, sensory, and motor disabilities. Thus, the aims of our study were (1) to determine the validity of waist circumference measurements obtained in a supine position, (2) to formulate an equation that predicts standing waist circumference from measurements obtained in a supine position, and (3) to determine the reliability of measuring waist circumference in persons with severe intellectual, sensory, and motor disabilities. First, we performed a validity study in 160 healthy participants, in which we compared waist circumference obtained in standing and supine positions. We also conducted a test-retest study in 43 participants with severe intellectual, sensory, and motor disabilities, in which we measured the waist circumference with participants in the supine position. Validity was assessed with paired t-test and Wilcoxon signed rank test. A prediction equation was estimated with multiple regression analysis. Reliability was assessed by Wilcoxon signed rank test, limits of agreement (LOA), and intraclass correlation coefficients (ICC). Paired t-test and Wilcoxon signed rank test revealed significant differences between standing and supine waist circumference measurements. We formulated an equation to predict waist circumference (R(2)=0.964, p<0.001). There were no significant differences between test and retest waist circumference values in disabled participants (p=0.208; Wilcoxon signed rank test). The LOA was 6.36 cm, indicating a considerable natural variation at the individual level. ICC was .98 (p<0.001). We found that the validity of supine waist circumference is biased towards higher values (1.5 cm) of standing waist circumference. However, standing waist circumference can be predicted from supine measurements using a simple prediction equation. This equation allows the comparison of supine measurements of disabled persons with the international standards. Supine waist circumference can be reliably measured in participants with severe intellectual, sensory, and motor disabilities.

Research in developmental disabilities, 2010 · doi:10.1016/j.ridd.2010.02.009