Latent Variable Growth Curve and Mixture Models for Life Course Epidemiology

Lead Research Organisation: University of Leeds
Department Name: Lds Inst Genetics Health & Therapeutics

Abstract

Preventing chronic illnesses such as cancer and cardiovascular disease requires a better understanding of their causes. The importance of adulthood risk factors such as smoking and diet are familiar to most people. However, research suggests that many of the diseases we face in adulthood may also be influenced by factors we experience in childhood, infancy, and even before we are born.

To better understand these life course influences on disease risk, epidemiologists study cohorts of people that are followed up for a long period of time, often from birth. These kinds of studies have become more common over the past thirty years, but it is not entirely clear which statistical methods are best suited to analyze these data.

My research aims to explore and demonstrate the usefulness of two advanced statistical methods for life course researchers. Using latent growth curve models and growth mixture models, I will investigate how infant and childhood growth patterns are related to obesity, using data from several existing studies. Research findings will be disseminated in a manner that facilitates the use of these methods by other researchers without advanced statistical training.

Technical Summary

Life course epidemiology is the study of physical and social exposures occurring across the entire life course on chronic disease risk later in life. Though the life course approach to chronic disease epidemiology is not new, it was overshadowed during much of the 20th century by research on adulthood lifestyle risk factors such as smoking or diet. However, life course theories on chronic disease have recently regained some prominence, and the Medical Research Council has identified the life course perspective as a key component of its research priority theme ‘Living a long and healthy life.‘

Testing life course theories of chronic disease depends on the collection and analysis of birth cohort and other longitudinal data. Birth cohort data are becoming more available, and practical guidance on longitudinal data collection is abundant. However, there is little advice on the application of statistical methods to analyze these data in a life course framework, except that methods should emphasise temporal and causal hierarchies among variables while addressing other issues such as missing data, measurement error, and the inclusion of latent variables. Some analytical methods, (e.g. multilevel models, path analysis, structural equation modelling, Markov models, marginal structural modelling, and G-estimation) have been briefly highlighted in the literature, but few advanced statistical methods have been clearly demonstrated for an audience of life course epidemiologists.

The aim of my research is to explore and demonstrate the usefulness of latent growth curve models (LGCM) and growth mixture models (GMM) for life course epidemiology. I will accomplish this by first linking LGCM and GMM to existing auxological theory and statistical methods. I will then apply these methods to explore how infant and childhood growth patterns in height and body mass are related to obesity and related metabolic outcomes in young adulthood. Data come from five birth cohort stu from lower and middle-income contexts. While the results from this analysis will meaningfully contribute to existing research, the ultimate goal of this research is to facilitate the use of these methods by other life course researchers, especially those without a background in advanced statistics. Thus research findings published in high impact public health journals will be matched to web-based learning materials and papers published in methodological journals that dissect these methods for a broader epidemiological audience.
 
Description Whitehead Travel Scholarship
Amount £2,100 (GBP)
Organisation University of Leeds 
Sector Academic/University
Country United Kingdom
Start 12/2012 
End 11/2013
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation Chinese University of Hong Kong
Country Hong Kong 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation National University of Defense Technology
Country China 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation University of Auckland
Country New Zealand 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation University of Bristol
Country United Kingdom 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation University of Western Australia
Country Australia 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Advanced Methodologies for strengthening the evidence base for Public Health Action in Societies under Transition (AMPHAST) 
Organisation University of Wisconsin-Madison
Country United States 
Sector Academic/University 
PI Contribution This is a new partnership, funded by the World Universities Network. To date we have only had one meeting.
Collaborator Contribution NA (new partnership)
Impact NA (new partnership)
Start Year 2012
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation Emory University
Department Emory Global Health Institute
Country United States 
Sector Academic/University 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation Federal University of Pelotas (UFPel)
Department Department of Epidemiology
Country Brazil 
Sector Academic/University 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation University of North Carolina at Chapel Hill
Department UNC Nutrition Research Institute
Country United States 
Sector Academic/University 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation University of San Carlos
Department Office of Population Studies
Country Philippines 
Sector Academic/University 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation University of Southampton
Department MRC Lifecourse Epidemiology Unit
Country United Kingdom 
Sector Public 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description Consortium on Health Orientated Research in Transitional Societies (COHORTS) 
Organisation University of the Witwatersrand
Department Birth to Twenty
Country South Africa 
Sector Academic/University 
PI Contribution I provide opinions and guidance for statistical analyses (primarily longitudinal and latent variable methods) to members of the group. This happens by request, or at our regular meetings (usually twice a year). I participate in writing groups for peer reviewed publications. I am currently leading two writing groups for peer review publications.
Collaborator Contribution The collaboration is a large one, involving 5 birth cohort studies and at least 2 participants associated with each study. Design, collection, and management of cohort data. Identification of key research questions and agendas. Applications for funding (Wellcome Trust, Gates Foundation). Leading and participating in writing teams for peer reviewed publications.
Impact 5 published, peer-reviewed papers in high impact journals. 2 rounds of funding from the Wellcome Trust. 1 round of funding from the Gates Foundation. Disciplines: Psychology; Epidemiology; Biostatistics; Nutrition; Global health; Anthropology; Economics
Start Year 2006
 
Description RSS Getstats 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Provided a short essay on how to interpret growth charts.

NA
Year(s) Of Engagement Activity 2012