Color-Coding Improves Parental Understanding of Body Mass Index Charting
Received 5 February 2009; accepted 25 May 2009. published online 17 August 2009.
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.
Division of General Pediatrics and Adolescent Medicine (Ms Finkle and Dr Perrin), Division of General Medicine and Clinical Epidemiology (Dr Esserman), and Department of Pediatrics (Ms Finkle, Dr Whitehead, and Dr Perrin), University of North Carolina School of Medicine (Mr Oettinger and Mr Pattishall), Chapel Hill, NC; and Vanderbilt University School of Medicine (Mr Spain); and Center for Health Services Research, Vanderbilt University Medical Center (Dr Rothman), Nashville, Tenn
Address correspondence to Eliana M. Perrin, MD, MPH, University of North Carolina School of Medicine, Department of Pediatrics, Division of General Pediatrics and Adolescent Medicine, 231 MacNider Bldg, 333 S Columbia St, CB #7225, Chapel Hill. North Carolina 27599-7225.
ABSTRACT