Cargando…

Optimal design for longitudinal studies to estimate pubertal height growth in individuals

Background: The SITAR model expresses individual pubertal height growth in terms of mean size, peak height velocity (PHV) and age at PHV. Aim: To use SITAR to identify the optimal time interval between measurements to summarise individual pubertal height growth. Subjects and methods: Heights in 3172...

Descripción completa

Detalles Bibliográficos
Autor principal: Cole, Tim James
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Taylor & Francis 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191888/
https://www.ncbi.nlm.nih.gov/pubmed/29669435
http://dx.doi.org/10.1080/03014460.2018.1453948
_version_ 1783363799908089856
author Cole, Tim James
author_facet Cole, Tim James
author_sort Cole, Tim James
collection PubMed
description Background: The SITAR model expresses individual pubertal height growth in terms of mean size, peak height velocity (PHV) and age at PHV. Aim: To use SITAR to identify the optimal time interval between measurements to summarise individual pubertal height growth. Subjects and methods: Heights in 3172 boys aged 9–19 years from Christ’s Hospital School measured on 128 679 occasions (a median of 42 heights per boy) were analysed using the SITAR (SuperImposition by Translation And Rotation) mixed effects growth curve model, which estimates a mean curve and three subject-specific random effects. Separate models were fitted to sub-sets of the data with measurement intervals of 2, 3, 4, 6, 12 and 24 months, and the different models were compared. Results: The models for intervals 2–12 months gave effectively identical results for the residual standard deviation (0.8 cm), mean spline curve (6 degrees of freedom) and random effects (correlations >0.9), showing there is no benefit in measuring height more often than annually. The model for 2-year intervals fitted slightly less well, but needed just four-to-five measurements per individual. Conclusions: Height during puberty needs to be measured only annually and, with slightly lower precision, just four biennial measurements can be sufficient.
format Online
Article
Text
id pubmed-6191888
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Taylor & Francis
record_format MEDLINE/PubMed
spelling pubmed-61918882018-10-25 Optimal design for longitudinal studies to estimate pubertal height growth in individuals Cole, Tim James Ann Hum Biol Research Paper Background: The SITAR model expresses individual pubertal height growth in terms of mean size, peak height velocity (PHV) and age at PHV. Aim: To use SITAR to identify the optimal time interval between measurements to summarise individual pubertal height growth. Subjects and methods: Heights in 3172 boys aged 9–19 years from Christ’s Hospital School measured on 128 679 occasions (a median of 42 heights per boy) were analysed using the SITAR (SuperImposition by Translation And Rotation) mixed effects growth curve model, which estimates a mean curve and three subject-specific random effects. Separate models were fitted to sub-sets of the data with measurement intervals of 2, 3, 4, 6, 12 and 24 months, and the different models were compared. Results: The models for intervals 2–12 months gave effectively identical results for the residual standard deviation (0.8 cm), mean spline curve (6 degrees of freedom) and random effects (correlations >0.9), showing there is no benefit in measuring height more often than annually. The model for 2-year intervals fitted slightly less well, but needed just four-to-five measurements per individual. Conclusions: Height during puberty needs to be measured only annually and, with slightly lower precision, just four biennial measurements can be sufficient. Taylor & Francis 2018-04-18 /pmc/articles/PMC6191888/ /pubmed/29669435 http://dx.doi.org/10.1080/03014460.2018.1453948 Text en © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Paper
Cole, Tim James
Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title_full Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title_fullStr Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title_full_unstemmed Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title_short Optimal design for longitudinal studies to estimate pubertal height growth in individuals
title_sort optimal design for longitudinal studies to estimate pubertal height growth in individuals
topic Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191888/
https://www.ncbi.nlm.nih.gov/pubmed/29669435
http://dx.doi.org/10.1080/03014460.2018.1453948
work_keys_str_mv AT coletimjames optimaldesignforlongitudinalstudiestoestimatepubertalheightgrowthinindividuals