Differential estimates of underweight-for-age and growth related morbidity according to different growth standards in Indian children

Comparison of WHO 2006 Growth Standards and Synthetic Indian References in Assessing Growth in Normal Children and Children with Growth-Related Disorders

Introduction

A good screening tool, such as a growth chart, should distinguish between children with normal growth and those with perturbed growth. Suitability of synthetic Indian growth references for diagnosing growth-related disorders for under-five children has not been evaluated. To assess the validity of World Health Organization (WHO) 2006 standards vs synthetic Indian references (2019) (by comparing weight, height, body mass index (BMI), standard deviation scores (SDS) and the composite index of anthropometric failure (CIAF)) in differentiating normal children and children with growth-related disorders.

Methods

Records of 2188 children (0-60 months) attending a tertiary centre paediatric outpatient department (OPD) were retrospectively studied; 1854 children were healthy and 334 were diagnosed with growth-related disorders as per the European Society for Paediatric Endocrinology (ESPE) classification. The anthropometric parameters converted to Z-scores for weight-for-age (WAZ), height-for-age (HAZ), BMI-for-age (BAZ) and a CIAF were computed using WHO and synthetic charts; Student's t-test was used for assessing differences and Youden's index for validity.

Results

Disease status of children and anthropometric failure on WAZ, HAZ, BAZ and CIAF on both WHO and synthetic charts had a significant association (P-value <0.05). WAZ, HAZ on both charts and CIAF on synthetic chart had a fair to moderate agreement (Kappa statistics) with disease status as per diagnosis (P-value <0.05). The sensitivity and negative predictive value for all anthropometric parameters were higher for synthetic charts.

Conclusion

Indian charts were more sensitive for diagnosing growth-related disorders from birth to 60 months of age when compared to WHO growth standards.

Growth monitoring as an early detection tool: a systematic review

Growth monitoring of apparently healthy children aims at early detection of serious underlying disorders. However, existing growth-monitoring practices are mainly based on suboptimal methods, which can result in delayed diagnosis of severe diseases and inappropriate referrals. We did a systematic review to address two key and interconnected questions underlying growth monitoring: which conditions should be targeted, and how should abnormal growth be defined? We systematically searched for studies reporting algorithms for growth monitoring in children and studies comparing the performance of new WHO growth charts with that of other growth charts. Among 1556 identified citations, 69 met the inclusion criteria. Six target conditions have mainly been studied: Turner syndrome, coeliac disease, cystic fibrosis, growth hormone deficiency, renal tubular acidosis, and small for gestational age with no catch-up after 2 or 3 years. Seven algorithms to define abnormal growth have been proposed in the past 20 years, but their level of validation is low, and their overall sensitivities and specificities vary substantially; however, the Grote and Saari clinical decision rules seem the most promising. Two studies reported that WHO growth charts had poorer performance compared with other existing growth charts for early detection of target conditions. Available data suggest a large gap between the widespread implementation of growth monitoring and its level of evidence or the clinical implications of early detection of serious disorders in children. Further investigations are needed to standardise the practice of growth monitoring, with a consensus on a few priority target conditions and with internationally validated clinical decision rules to define abnormal growth, including the selection of appropriate growth charts.