Objective: To compare the prevalence of shortness, underweight, and overweight by using the Centers for Disease Control and Prevention (CDC) 2000 and the World Health Organization (WHO) 2006 growth charts. These comparisons are undertaken with 2 sets of cutoff values.
Study design: Data from the National Health and Nutrition Examination Survey 1999-2004 were used to calculate the prevalence estimates in US children aged 0 to 59 months (n = 3920). Cutoff values commonly used in the United States, on the basis of the 5th percentile of height-for-age to define shortness, the 5th percentile of weight-for-height or weight-for-age to define underweight, and the 95th percentile of weight-for-height or body mass index-for-age to define overweight were compared with the cutoff values recommended by WHO, which use <-2 z-score (equivalent to 2.3rd percentile) to define shortness and underweight and >or=2 z-score (equivalent to 97.7th percentile) to define overweight. A comparison with the same cutoff values (5th and 95th) in the 2 charts was also performed.
Results: Applying the 5th or 95th percentile, we observed a higher prevalence of shortness and overweight for all the age groups when the WHO 2006 growth charts were used than when the CDC 2000 growth charts were used. Applying the 5th percentile to the WHO 2006 charts produced lower rates of underweight than did the CDC 2000 charts. However, applying the 5th or 95th percentiles to the CDC 2000 charts and the WHO-recommended cutoff values of -2 or +2 z-score to the WHO charts produced smaller differences in the prevalence of shortness and overweight than were seen when the 5th and 95th percentiles were applied to both the CDC and WHO charts.
Conclusions: Estimates of the prevalence of key descriptors of growth in children aged 0 to 59 months vary by the chart used and the cutoff values applied. The use of the 5th and 95th percentiles for the CDC growth charts and the 2.3rd and 97.7th percentiles for the WHO growth charts appear comparable in the prevalence of shortness and overweight, but not underweight. If practitioners were to use the WHO growth charts, it might be more appropriate to adopt the WHO recommended cutoff values as well, but this would be a change for office practice.