TY  - INPR
KW  - CDC
KW  -  harmonization
KW  -  IOTF
KW  -  obesity
KW  -  overweight
KW  -  prevalence
KW  -  WHO
A1  - Cole, Tim J
A1  - Lobstein, Tim
JF  - Pediatric Obesity
PB  - WILEY
UR  - https://doi.org/10.1111/ijpo.12970
ID  - discovery10155184
N2  - BACKGROUND: Prevalence rates of child overweight and obesity for a group of children vary depending on the BMI reference and cut-off used. Previously we developed an algorithm to convert prevalence rates based on one reference to those based on another. OBJECTIVE: To improve the algorithm by combining information on overweight and obesity prevalence. METHODS: The original algorithm assumed that prevalence according to two different cut-offs A and B differed by a constant amount  dz $$ dz $$  on the z-score scale. However the results showed that the z-score difference tended to be greater in the upper tail of the distribution and was better represented by  b × dz $$ b\times dz $$  , where  b $$ b $$  was a constant that varied by group. The improved algorithm uses paired prevalence rates of overweight and obesity to estimate  b $$ b $$  for each group. Prevalence based on cut-off A is then transformed to a z-score, adjusted up or down according to  b × dz $$ b\times dz $$  and back-transformed, and this predicts prevalence based on cut-off B. The algorithm's performance was tested on 228 groups of children aged 6-17?years from 20 countries. RESULTS: The revised algorithm performed much better than the original. The standard deviation (SD) of residuals, the difference between observed and predicted prevalence, was 0.8% (n = 2320 comparisons), while the SD of the difference between pairs of the original prevalence rates was 4.3%, meaning that the algorithm explained 96.7% of the baseline variance (88.2% with original algorithm). CONCLUSIONS: The improved algorithm appears to be effective at harmonizing prevalence rates of child overweight and obesity based on different references.
N1  - © 2022 The Authors. Pediatric Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/).
EP  - 10
Y1  - 2022/08/23/
AV  - public
TI  - An improved algorithm to harmonize child overweight and obesity prevalence rates
ER  -