Introducing a drift and diffusion framework for childhood growth research
Open Access
- 29 June 2020
- journal article
- Published by F1000 Research Ltd in Gates Open Research
Abstract
Background: Growth trajectories are highly variable between children, making epidemiological analyses challenging both to the identification of malnutrition interventions at the population level and also risk assessment at individual level. We introduce stochastic differential equation (SDE) models into child growth research. SDEs describe flexible dynamic processes comprising: drift - gradual smooth changes – such as physiology or gut microbiome, and diffusion - sudden perturbations, such as illness or infection. Methods: We present a case study applying SDE models to child growth trajectory data from the Haydom, Tanzania and Venda, South Africa sites within the MAL-ED cohort. These data comprise n=460 children aged 0-24 months. A comparison with classical curve fitting (linear mixed models) is also presented. Results: The SDE models offered a wide range of new flexible shapes and parameterizations compared to classical additive models, with performance as good or better than standard approaches. The predictions from the SDE models suggest distinct longitudinal clusters that form distinct ‘streams’ hidden by the large between-child variability. Conclusions: Using SDE models to predict future growth trajectories revealed new insights in the observed data, where trajectories appear to cluster together in bands, which may have a future risk assessment application. SDEs offer an attractive approach for child growth modelling and potentially offer new insights.Keywords
Funding Information
- Fogarty International Center
- Foundation for the National Institutes of Health
- Bill and Melinda Gates Foundation (OPP47075)
- National Institutes of Health
This publication has 22 references indexed in Scilit:
- The development of growth references and growth chartsAnnals of Human Biology, 2012
- Human gut microbiome viewed across age and geographyNature, 2012
- SITAR—a useful instrument for growth curve analysisInternational Journal of Epidemiology, 2010
- Maternal and child undernutrition: consequences for adult health and human capitalThe Lancet, 2008
- Maternal and child undernutrition: global and regional exposures and health consequencesThe Lancet, 2008
- Seeing the Wood for the Trees: A Critical Evaluation of Methods to Estimate the Parameters of Stochastic Differential EquationsJournal of Financial Econometrics, 2007
- WHO Child Growth Standards based on length/height, weight and ageActa Paediatrica, 2006
- Option Pricing in Stochastic Volatility Models of the Ornstein‐Uhlenbeck typeMathematical Finance, 2003
- Using Growth Curve Analysis to Evaluate Child Change in Longitudinal InvestigationsJournal of Early Intervention, 1994
- Classification and definition of protein-calorie malnutrition.BMJ, 1972