scholarly journals Estimation of Individual Growth Trajectories When Repeated Measures Are Missing

2017 ◽  
Vol 190 (3) ◽  
pp. 377-388 ◽  
Author(s):  
Mollie E. Brooks ◽  
Christopher Clements ◽  
Josephine Pemberton ◽  
Arpat Ozgul
Keyword(s):  
Repeated Measures ◽  
Individual Growth ◽  
Growth Trajectories

scholarly journals Comparison of growth models to describe growth from birth to 6 years in a Beninese cohort of children with repeated measurements

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e035785
Author(s):  
Shukrullah Ahmadi ◽  
Florence Bodeau-Livinec ◽  
Roméo Zoumenou ◽  
André Garcia ◽  
David Courtin ◽  
...  
Keyword(s):  
Growth Model ◽  
Goodness Of Fit ◽  
Growth Models ◽  
Information Criterion ◽  
Height Growth ◽  
Sub Saharan Africa ◽  
Individual Growth ◽  
Secondary Outcome ◽  
Growth Trajectories ◽  
Best Fitting

ObjectiveTo select a growth model that best describes individual growth trajectories of children and to present some growth characteristics of this population.SettingsParticipants were selected from a prospective cohort conducted in three health centres (Allada, Sekou and Attogon) in a semirural region of Benin, sub-Saharan Africa.ParticipantsChildren aged 0 to 6 years were recruited in a cohort study with at least two valid height and weight measurements included (n=961).Primary and secondary outcome measuresThis study compared the goodness-of-fit of three structural growth models (Jenss-Bayley, Reed and a newly adapted version of the Gompertz growth model) on longitudinal weight and height growth data of boys and girls. The goodness-of-fit of the models was assessed using residual distribution over age and compared with the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The best-fitting model allowed estimating mean weight and height growth trajectories, individual growth and growth velocities. Underweight, stunting and wasting were also estimated at age 6 years.ResultsThe three models were able to fit well both weight and height data. The Jenss-Bayley model presented the best fit for weight and height, both in boys and girls. Mean height growth trajectories were identical in shape and direction for boys and girls while the mean weight growth curve of girls fell slightly below the curve of boys after neonatal life. Finally, 35%, 27.7% and 8% of boys; and 34%, 38.4% and 4% of girls were estimated to be underweight, wasted and stunted at age 6 years, respectively.ConclusionThe growth parameters of the best-fitting Jenss-Bayley model can be used to describe growth trajectories and study their determinants.

scholarly journals Growth potential can affect timing of maturity in a long-lived semelparous fish

2018 ◽  
Vol 14 (7) ◽  
pp. 20180269 ◽  
Author(s):  
Kazuki Yokouchi ◽  
Françoise Daverat ◽  
Michael J. Miller ◽  
Nobuto Fukuda ◽  
Ryusuke Sudo ◽  
...  
Keyword(s):  
Anguilla Anguilla ◽  
Growth Conditions ◽  
Growth Potential ◽  
Individual Growth ◽  
Growth Trajectories ◽  
Female Size ◽  
European Eel ◽  
Growth And Survival ◽  
Silver Eels ◽  
Reproduction Cost

Many diadromous fishes such as salmon and eels that move between freshwater and the ocean have evolved semelparous reproductive strategies, but both groups display considerable plasticity in characteristics. Factors such as population density and growth, predation risk or reproduction cost have been found to influence timing of maturation. We investigated the relationship between female size at maturity and individual growth trajectories of the long-lived semelparous European eel, Anguilla anguilla . A Bayesian model was applied to 338 individual growth trajectories of maturing migration-stage female silver eels from France, Ireland, the Netherlands and Hungary. The results clearly showed that when growth rates declined, the onset of maturation was triggered, and the eels left their growth habitats and migrated to the spawning area. Therefore, female eels tended to attain larger body size when the growth conditions were good enough to risk spending extra time in their growth habitats. This flexible maturation strategy is likely related to the ability to use diverse habitats with widely ranging growth and survival potentials in the catadromous life-history across its wide species range.

scholarly journals Growth Trajectories in Genetic Subtypes of Prader–Willi Syndrome

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 736
Author(s):  
Daisy A. Shepherd ◽  
Niels Vos ◽  
Susan M. Reid ◽  
David E. Godler ◽  
Angela Guzys ◽  
...  
Keyword(s):  
Mixed Models ◽  
Repeated Measures ◽  
Molecular Subtypes ◽  
Growth Trajectories ◽  
Prader Willi Syndrome ◽  
Growth Data ◽  
Expression Of Genes ◽  
Subject Specific ◽  
Data Points ◽  
Autoregressive Correlation

Prader–Willi syndrome (PWS) is a rare disorder caused by the loss of expression of genes on the paternal copy of chromosome 15q11-13. The main molecular subtypes of PWS are the deletion of 15q11-13 and non-deletion, and differences in neurobehavioral phenotype are recognized between the subtypes. This study aimed to investigate growth trajectories in PWS and associations between PWS subtype (deletion vs. non-deletion) and height, weight and body mass index (BMI). Growth data were available for 125 individuals with PWS (63 males, 62 females), of which 72 (57.6%) had the deletion subtype. There was a median of 28 observations per individual (range 2–85), producing 3565 data points distributed from birth to 18 years of age. Linear mixed models with cubic splines, subject-specific random effects and an autoregressive correlation structure were used to model the longitudinal growth data whilst accounting for the nature of repeated measures. Height was similar for males in both PWS subtypes, with non-deletion females being shorter than deletion females for older ages. Weight and BMI were estimated to be higher in the deletion subtype compared to the non-deletion subtype, with the size of difference increasing with advancing age for weight. These results suggest that individuals with deletion PWS are more prone to obesity.

Language, motor and cognitive development of extremely preterm children: Modeling individual growth trajectories over the first three years of life

2014 ◽  
Vol 49 ◽  
pp. 55-68 ◽  
Author(s):  
Alessandra Sansavini ◽  
Jill Pentimonti ◽  
Laura Justice ◽  
Annalisa Guarini ◽  
Silvia Savini ◽  
...  
Keyword(s):  
Cognitive Development ◽  
Individual Growth ◽  
Growth Trajectories ◽  
Preterm Children ◽  
Extremely Preterm

scholarly journals High-Frequency Repeated Measures of Over 5,000 Infants Aged 6–27 Months Reveals Pattern of Growth Faltering in Rural Burkina Faso

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 636-636
Author(s):  
Ilana Cliffer ◽  
William Masters ◽  
Elena Naumova ◽  
Nandita Perumal ◽  
Beatrice Rogers
Keyword(s):  
Burkina Faso ◽  
Growth Velocity ◽  
Repeated Measures ◽  
Growth Curves ◽  
The United States ◽  
Individual Growth ◽  
Food Aid ◽  
Initial Length ◽  
Growth Faltering ◽  
Increased Risk

Abstract Objectives Linear growth faltering, failure to achieve one's potential for length or height at each age, is associated with increased risk of mortality and morbidity. Understanding the age-related patterns of growth faltering can inform timing of interventions and policies for prevention; however current knowledge is limited by cross-sectional data. We examine the longitudinal characterization of the timing of growth faltering among young children. Methods Using longitudinal anthropometric data originally collected as part of a food-aid cost-effectiveness trial, we investigated individual growth curves of 5,039 children aged 6–27 months in Burkina Faso (108,580 total measurements) to determine whether growth faltering occurs through intermittent episodes of slower growth, or continuously slow growth. We visualized individual growth curves and used two-stage regressions to evaluate growth curve smoothness at different levels of attained length. To do this, we first obtained model fit and diagnostic parameters from individual regressions of each child's length on their age. Parameters extracted included R2, as a metric of curve smoothness, initial length at 6 months, and average velocity. We then regressed these parameters on individual-level attained length at study end. Results Growth faltering manifests as both continuously lower growth velocity throughout the observation period and greater heterogeneity in growth velocity amplitude. Children with lower attained length start smaller (Quintile 1 of attained length-63.1 cm initial length; Quintile 5-68.4 cm) and stay on their initial trajectories, continuously growing slower than their taller counterparts. In addition, a 0.01 increase in the R2 (smoothness) from regression of a child's length on their age is associated with a 3.10 cm increase in attained length (95% CI: 2.80, 3.41), showing that smoother growth is also associated with higher attained length. Conclusions Children who experience the most extreme growth faltering are likely to be less resilient to systematic growth-limiting conditions as well as episodic insults to their growth. Future research should investigate ways of improving environmental conditions to support growth. Funding Sources Financial support provided by the Food Aid Quality Review project, funded by the United States Agency for International Development.

scholarly journals Effects of species invasion on population dynamics, vital rates, and life histories of the native species

2017 ◽  
Author(s):  
Simone Vincenzi ◽  
Alain J Crivelli ◽  
Dusan Jesensek ◽  
Ellen Campbell ◽  
John C Garza
Keyword(s):  
Population Dynamics ◽  
Rainbow Trout ◽  
Native Species ◽  
Life Histories ◽  
Life History Theory ◽  
Individual Growth ◽  
Growth Trajectories ◽  
Natural Environments ◽  
Vital Rates ◽  
Marble Trout

AbstractInvasions occurring in natural environments provide the opportunity to study how vital rates change and life histories evolve in the presence of a competing species. In this work, we estimate differences in reproductive traits, individual growth trajectories, survival, life histories, and population dynamics between a native species living in allopatry and in sympatry with an invasive species of the same taxonomic Family. We used as a model system marble trout Salmo marmoratus (native species) and rainbow trout Oncorhynchus mykiss (non-native) living in the Idrijca River (Slovenia). An impassable waterfall separates the stream in two sectors only a few hundred meters apart: a downstream sector in which marble trout live in sympatry with rainbow trout and a upstream sector in which marble trout live in allopatry. We used an overarching modeling approach that uses tag-recapture and genetic data (> 2,500 unique marble and rainbow trout were sampled and SNP-genotyped) to reconstruct pedigrees, test for synchrony of population dynamics, and model survival and growth while accounting for individual heterogeneity in performance. The population dynamics of the two marble trout populations and of rainbow trout were overall synchronous. We found higher prevalence of younger parents, higher mortality, and lower population density in marble trout living in sympatry with rainbow trout than in marble trout living in allopatry. There were no differences in the average individual growth trajectories between the two marble trout populations. Faster life histories of marble trout living in sympatry with rainbow trout are consistent with predictions of life-history theory.

Sign in / Sign up

Export Citation Format

Share Document