Meet Kylie Hunter, PhD candidate, NHMRC Clinical Trials Centre, University of Sydney

Kylie commenced her PhD at the NHMRC Clinical Trials Centre, University of Sydney in July 2020 under the primary supervision of Professor Ian Marschner. She is also lucky enough to have the support of multiple auxiliary supervisors: Prof Louise Baur, Prof Rebecca Golley, Prof Lisa Askie, Dr Kristy Robledo and Anna Lene Seidler. Kylie was successful in obtaining a University of Sydney Postgraduate Award and a Postgraduate Research Supplementary Scholarship in Methods Development to support her work.

The main focus of Kylie's PhD is a systematic review with individual participant data (IPD) meta-analysis evaluating behavioural interventions for the prevention of early childhood obesity. This is project 1 of the Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration, which is chaired by Anna Lene Seidler, and supported by an NHMRC Ideas Grant (see

TOPCHILD aims: 1) to bring together all completed, ongoing and planned trials evaluating very early behavioural interventions, commencing during pregnancy or the first year of life for the prevention of obesity in children at 2 years; and 2) to combine the innovative methodologies, individual participant data meta-analysis (Project 1), deconstructing interventions (Project 2) and predictive modelling (Project 3), to determine the effectiveness of these interventions, as well as which intervention components work and for whom.

Kylie's work will build on the EPOCH prospective meta-analysis undertaken by Stream 1 by leveraging individual participant data from the more than 60 relevant trials that have since been identified. These trials have an estimated combined sample size of >30,000 participants, thus making this the largest IPD meta-analysis to date evaluating behavioural interventions for the prevention of early childhood obesity. The primary outcome will be BMI z-score and secondary outcomes include other measures of child weight, early feeding practices, dietary quality, screen time, sleep, activity and adverse events, as well as parent-related measures such as parenting self-efficacy.

Using IPD meta-analysis methodology will provide the most reliable and precise estimates of intervention effect and enable in-depth exploration of key participant level and trial/intervention level characteristics, such as socioeconomic position and current level of background care in the community. The project will also include a nested prospective meta-analysis for planned/ongoing studies. This will facilitate data harmonisation and enable exploration of potential selection bias and publication bias by comparing prospectively vs retrospectively included studies.

The deconstructing component of TOPCHILD (Project 2), is led by EPOCH EMCR, Dr Brittany Johnson from Flinders University. It aims to deconstruct early obesity prevention interventions into their components, including target behaviours, delivery features and Behaviour Change Techniques, using standardised coding taxonomies and new ontologies. The third project will involve developing prediction models using the combined trial database including both study level (intervention components) and individual level (participant) factors.

The knowledge generated from the work of the TOPCHILD Collaboration can be used to inform the design and implementation of more effective, efficient, equitable and targeted interventions for the prevention of childhood obesity and associated consequences.

Kylie also plans to conduct a number of methodological projects on evidence synthesis and research transparency to complement her TOPCHILD work and complete her PhD.

For more details, please contact: Kylie Hunter at