Bmi children percentile calculation how to#
Bmi children percentile calculation code#

Severe obesity growth charts previously published by others were based on a measure called percent of the 95th percentile-a statistical calculation-and not on actual growth data of children with very high BMIs. Learn more about CDC-Recognized Family Healthy Weight Programs which are ready-to-use, evidence-based child obesity programs.

The new growth charts coupled with high-quality treatment help optimize care for children with severe obesity.

Growth charts for children and adolescents without obesity, and their recommended use, have not changed. The 2022 CDC Extended BMI-for-Age Growth Charts can help providers track growth and optimize care for children and adolescents with very high BMIs (above the 97th percentile). Because of this, CDC expanded the growth charts using more recent data and methods, and added new percentile curves to the growth charts for tracking children and adolescents with very high BMIs. The 2000 CDC BMI-for-Age Growth Charts have a maximum plottable BMI of 37 kg/m 2 and no percentile lines above the 95th percentile, which makes them less useful as a visual growth tracking tool for children with severe obesity. The 2000 CDC BMI-for-Age Growth Charts are based on reference data from 1963 to 1980, a period when the prevalence of obesity was lower than today and when growth data for children with severe obesity were sparse. Among children aged 2–19 years, the prevalence of severe obesity has increased from 1% in 1971–74 to 6.1% in 2017–18. Severe obesity is defined as BMI at or above 120% of the 95th percentile for sex and age, or BMI at or above 35 kg/m 2. If someone could help me use zanthro (or something similar) as a basis to produce the 95th percentile for any given age-gender, I could do the rest of the calculations to get bmipct95 and/or bmidif95.Childhood obesity is a serious problem in the United States, putting children and adolescents at risk for poor health outcomes during childhood, adolescence, and adulthood.

Bmi children percentile calculation how to#

But I don't know how to yield the 95th percentile for any particular age, gender combination. I am aware of the zanthro command to calculate bmi z-scores, and I know how to convert those z-scores into BMI percentiles. I'm wondering if anyone knows of a Stata command that can do the same thing (i.e., use child BMI, age, and gender to produce a variable containing BMI relative to the 95th percentile, or even just produce the specific 95th percentile for any age, gender combination ). The limitations of expressing extremely high BMIs as z-scores apply to both cross-sectional and longitudinal studies, including those that evaluate obesity interventions. If a large proportion of children in an analysis have severe obesity (bmipct95 ≥ 120), you should consider expressing all BMIs relative to the 95 th percentile and using bmipct95 or bmidif95 in analyses. In addition to these 2 variables, the SAS program also outputs the CDC 50th ( bmi50) and 95 th ( bmi95) percentiles for the child's sex and age. A negative value for bmidif95 (or a bmipct95 < 100) would indicate that the child does not have obesity. For example, the CDC 95 th percentile for a 20-month-old boy is 18.0 kg/m 2 if this boy had a BMI of 21.3kg/m 2, his bmidif95 would be 3.3 kg/m 2 (21.3 - 18.0) and his bmipct95 would be 118% (100 × 21.3/18.0).

Bmidif95 is the difference (in kg/m 2) between the child's BMI and the CDC 95 th percentile for that sex/age. Bmipct95 can range from below 50 to over 220, and a child with a bmipct95 of 140 would have a BMI that is equal to 1.4 times the 95th percentile. These 2 variables are likely to be better measures of adiposity among children who have very high BMIs than are z-scores and percentiles.

Bmi children percentile calculation code#

The SAS code creates 2 variables, bmipct95 and bmidif95, that express a child's BMI relative to the 95 th percentile either as a percentage (bmipct95) or as a difference (bmidif95). The drawbacks of expressing very high BMIs as z-scores (or percentiles) have been emphasized by several investigators.