Color-coding improves parental understanding of body mass index charting

Acad Pediatr. 2009 Sep-Oct;9(5):330-8. doi: 10.1016/j.acap.2009.05.028. Epub 2009 Aug 13.


Objective: To assess parental understanding of body mass index (BMI) and BMI percentiles by using standard versus color-coded charts; to investigate how parental literacy and/or numeracy (quantitative skills) affects that understanding.

Methods: A convenience sample of 163 parents of children aged 2 to 8 years at 2 academic pediatric centers completed a demographics questionnaire, the mathematics portion of the Wide Range Achievement Test (WRAT-3R), the Short Test of Functional Health Literacy in Adults (S-TOFHLA), and an "Understanding BMI" questionnaire, which included parallel BMI charting questions to compare understanding of standard versus color-coded BMI charting. Outcomes included parental-reported versus actual understanding of BMI, the odds (obtained by generalized estimating equations) of answering parallel questions correctly by using standard versus color-coded charting, and odds of answering questions correctly on the basis of numeracy and literacy.

Results: Many parents (60%) reported knowing what BMI was, but only 30% could define it even roughly correctly. When parents used color-coded charts, they had greater odds of answering parallel BMI charting questions correctly than when they used standard charts (mean, 88% vs 65% correct; pooled adjusted odds ratio, 4.32; 95% confidence interval, 3.14-5.95; P < .01). Additionally, parents with lower numeracy (K-5 level) benefited more from color-coded charts (increased from 51% to 81% correct) than did higher numeracy parents (high school level or greater), who performed well with both charts (89% vs 99% correct).

Conclusions: Parents consistently performed better with color-coded than standard BMI charts. Color-coding was particularly helpful for lower numeracy parents. Future studies should investigate whether these results translate into the office setting and whether understanding motivates parents to implement important lifestyle changes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index*
  • Child
  • Color
  • Comprehension
  • Educational Status
  • Growth Charts*
  • Health Literacy*
  • Humans
  • Parents / psychology*