Background and aims WHO Growth Standards (WHO) for children under 5 published in 2006 have been adopted by many countries. The data used to construct the WHO standard did not include data from East Asia. South Korea has a policy of making their own growth charts to reflect their rapid secular trend in height. The aim of this analysis was to assess how South Korean data compare to WHO and the implications this would have if adopted.
Methods Cross sectional data for children under 60 months of age from two Korean nationwide anthropometric surveys, collected in 1997 (N=53,048) and 2005 (N=62,257) were used. Data were collected via community surveys over age 2 years, but mainly in hospitals, at younger ages. All measurements were converted into SD scores using the zanthro program in STATA version 12 and a macro program from WHO, compared to both WHO and the latest version of Korean growth charts (KOREAN) which was produced using pooled data of 97DATA and 05DATA.
Results Secular change was seen between 1997 and 2005, with a mean gain in length/height of 0.34 SDS when compared to WHO (table 1). Children in the 2005 appeared progressively taller compared to WHO during the early months (mean length SDS age 6 m: 0.98), but tracked within ±0.3 SD of WHO median from age 27-60 months. Using 2005 data, the prevalence of overweight (BMI above 98th centile) was higher using WHO (5.0%) compared to KOREAN (2.5%), but the prevalence of underweight (below 2nd centile) was decreased (KOREAN=2.6%; WHO=0.9%). More stunting (height below 2nd centile) was seen using WHO (WHO=2.0% KOREAN=1.4%).
Conclusions Korean data collected from community based sampling fits the WHO Standards well. WHO demonstrates secular change more clearly than the Korean reference based on data pooled over time. Changes in the rates of overweight and stunting would be expected if WHO was adopted.