Objective: To examine the accuracy of World Health Organization (WHO) growth standard in under-5 year Indian children, and identify a method to contextualize the WHO standard for India.
Participants: Data of Healthy children, defined by WHO selection criteria, extracted from nationally representative Indian surveys (National Family Health Surveys, NFHS-3, NFHS-4, NFHS-5 and Comprehensive National Nutrition Survey, CNNS).
Design: Height for age z score (HAZ) and weight for age z score (WAZ) and weight for height z score (WHZ) distributions in healthy sample were compared against the standard normal. If deviant, age-specific correction factors for z scores were estimated by hierarchical linear mixed effects mean and variance polynomial models. A new term, excess mean risk of growth faltering (EMRGF), was introduced to describe growth faltering.
Main outcome: Measure of deviation of HAZ, WAZ and WHZ from standard normal distribution. Correction of WHO growth standards for India leading to accurate prevalence of stunting, underweight and wasting in Indian children using NFHS-5 data.
Results: Data on 10,384 healthy under-5 year children were extracted, of which 5377 were boys. Across surveys and metrics, the mean z scores were significantly lower than zero (-0.52 to -0.79). HAZ and WHZ variability (1.16, 1.07) were significantly higher than 1. Derived age-specific corrections reduced the NFHS-5 prevalence of growth faltering by 50%. The national EMRGF (after applying the age-specific correction) for height for age was 15.5% (95%CI:15.3-15.8), and weight for age was 15.0% (95%CI:14.8-15.3), respectively, in NFHS-5.
Conclusion: The WHO growth standards need contextual customization for accurate estimation of the burden of growth faltering in under-5 year children in India. When corrected, the burden of growth faltering is lower, by half or more, in all the three indices.