Conditional Growth References for Vietnamese Children: Quantile Regression of Growth Distributions and Phenotypes
- 1Vinmec International Hospital, Hanoi, Vietnam
Abstract
Background and objectiveThe WHO growth reference judges a childs height against the population at one age, without using the childs own earlier growth. This study built and validated a quantile regression based conditional growth reference predicting a childs future height for age distribution from early growth status.
MethodsUsing deidentified longitudinal annual school children health check data from three major cities in Vietnam, this study linked a baseline height and BMI for age Z score near age 6 to outcome visits near age 12 or 15 in 4,857 children. A linear quantile regression and a pooled quantile generalized additive model, fit by sex, were compared against a linear benchmark and a naive persistence model on a held out test set, using pinball loss, interval coverage, and width against the WHO 90% band. This study also tested adding growth phenotype and checked generalization across the three cities.
ResultsThe pooled model outperformed the discrete quantile regression in every group. Every individualized 90% interval was narrower than the WHO band, by 34.6 to 54.5%. Growth phenotype improved accuracy in most groups. The model generalized well to a held out Hanoi or Haiphong but poorly to a held out Ho Chi Minh City, where coverage fell to between 0.35 and 0.52, though the all-city model stayed well calibrated for Ho Chi Minh City itself.
ConclusionConditional quantile modeling gives individualized growth predictions markedly narrower than a fixed population reference and gains further from growth phenotype, but needs local validation before use at an unrepresented site.
Related
- Distinct Peri-pubertal Growth Phenotypes Among Vietnamese Urban Children: A Functional Clustering Analysis of 2018-2025 School Health Data
- The Age-Varying Association Between BMI and Height-for-Age in Vietnamese Schoolchildren: A Sex-Stratified Quantile Regression Study
- Cell-specific conditional deletion of Pten in the uterus results in differential phenotypes
- Age- and sex-specific normative references and performance zones for core muscular endurance in adolescents aged 12–16 years: a cross-sectional study
- Gestational age references and trajectory of fetal haemoglobin in relation to outcome in neonates born before 30 weeks of gestation: a single-centre retrospective cohort study in The Netherlands
BibTeX
@misc{ho2026conditional,
title = {{Conditional Growth References for Vietnamese Children: Quantile Regression of Growth Distributions and Phenotypes}},
author = {N. T. Ho},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.23.26363771},
url = {https://www.medrxiv.org/content/10.64898/2026.09.23.26363771v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Conditional Growth References for Vietnamese Children: Quantile Regression of Growth Distributions and Phenotypes
AU - N. T. Ho
PY - 2026
DA - 2026/09/23
PB - medRxiv
DO - 10.64898/2026.09.23.26363771
UR - https://www.medrxiv.org/content/10.64898/2026.09.23.26363771v1
AB - Background and objectiveThe WHO growth reference judges a childs height against the population at one age, without using the childs own earlier growth. This study built and validated a quantile regression based conditional growth reference predicting a childs future height for age distribution from early growth status. MethodsUsing deidentified longitudinal annual school children health check data from three major cities in Vietnam, this study linked a baseline height and BMI for age Z score near age 6 to outcome visits near age 12 or 15 in 4,857 children. A linear quantile regression and a pooled quantile generalized additive model, fit by sex, were compared against a linear benchmark and a naive persistence model on a held out test set, using pinball loss, interval coverage, and width against the WHO 90% band. This study also tested adding growth phenotype and checked generalization across the three cities. ResultsThe pooled model outperformed the discrete quantile regression in every group. Every individualized 90% interval was narrower than the WHO band, by 34.6 to 54.5%. Growth phenotype improved accuracy in most groups. The model generalized well to a held out Hanoi or Haiphong but poorly to a held out Ho Chi Minh City, where coverage fell to between 0.35 and 0.52, though the all-city model stayed well calibrated for Ho Chi Minh City itself. ConclusionConditional quantile modeling gives individualized growth predictions markedly narrower than a fixed population reference and gains further from growth phenotype, but needs local validation before use at an unrepresented site.
ER -