Accuracy of body mass index in categorizing weight status in children with intellectual and developmental disabilities.
Michele Polfuss, Bethany Forseth, Dale A Schoeller and 6 others
PMID 34542044WHAT IT FOUND
Body mass index misclassified weight status in 61% of children with disabilities compared to 11% of typically developing peers.
For wheelchair users, BMI failed to identify obesity in every case assessed, underestimating weight status by up to three categories.
Key findings
01BMI misclassified the weight status of 14 of 23 children with disabilities (61%) compared to 1 of 9 typically developing children (11%).
02All seven children with spina bifida who used wheelchairs were misclassified by BMI, with underestimation occurring in 86% of misclassifications among children with disabilities.
03When using a reference curve limited to older children, BMI still misclassified 43.7% of children with disabilities versus 16.6% of those without.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTsWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample size was very small (32 children), limiting the generalizability of the findings. The study did not assess the severity of the disability (e.g., lesion level in spina bifida or degree of hypotonia in Down syndrome), which likely influences body composition. Arm span was used as a surrogate for height in wheelchair users, but there is limited evidence supporting its accuracy for BMI calculation in this population. The primary reference curve used (Laurson) is based on skinfold measures, which may not perfectly reflect body fat in children with disabilities compared to whole-body measures like DXA. The Ogden reference curve (DXA-based) could only be used for children aged 8 and older, excluding younger participants from that specific comparison.
Declared interests
The authors reported no conflicts of interest. The study was supported by the National Institute of Child Health and Human Development.
The easy way to misread this
Do not assume that a 'normal' BMI percentile indicates a healthy weight in children with spina bifida or Down syndrome, particularly those who use wheelchairs. The study found that BMI consistently underestimated weight status in these groups, meaning obesity may be missed entirely if relying on this single metric.