Unfortunately, there is a need for extreme growth charts (Pediatrics 2012; 130: 1136-40).
The authors of this study designed growth charts for morbidly obese children. The reason for these charts is that there are many pediatric patients who cannot be plotted using the CDC growth chart which has a maximum BMI of 36 kg per meter-squared. The CDC charts are based on a preobesity epidemic population data set (1963-94) and has sparse data for those above the 97th percentile. The manuscript describes how these initial charts were derived.
These new growth charts calculate the BMI as a percentile of the 95th percentile. For example, multiplying the BMI 95th % by 1.2 would yield a result of 120% of the 95th%. The authors calculated 1.1 through 1.9 multiples of the 95% for all ages between 2 and 20 years. On their curve, a BMI as high as 64 kg per meter-squared can be plotted. This allows easier visual tracking of a patient’s progress.
Drawbacks:
- Difficult to explain to parents due to confusing phraseology –use of two percentages
- Many of the patients are now on the growth curve and could appear to be graphically normal despite being morbidly obese
The authors note that their growth charts were incorporated into their electronic medical record (Epic software).
Related blog entry:
gutsandgrowth 