Optimisation of children z-score calculation based on new statistical techniques

[EN] Background Expressing anthropometric parameters (height, weight, BMI) as z-score is a key principle in the clinical assessment of children and adolescents. The Centre for Disease Control and Prevention (CDC) growth charts and the CDC-LMS method for z-score calculation are widely used to assess growth and nutritional status, though they can be imprecise in some percentiles. Objective To improve the accuracy of z-score calculation by revising the statistical method using the original data used to develop current z-score calculators. Design A Gaussian Process Regressions (GPR) was designed and internally validated. Z-scores for weight-for-age (WFA), height-for-age (HFA) and BMI-for-age (BMIFA) were compared with WHO and CDC-LMS methods in 1) standard z-score cut-off points, 2) simulated population of 3000 children and 3) real observations 212 children aged 2 to 18 yo. Results GPR yielded more accurate calculation of z-scores for standard cut-off points (p<
The study presented in this paper was developed in the context of the MyCyFAPP Project, funded by the European Union under the Grant Agreement number 643806. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.