Transforming obesity prevention for CHILDren (TOPCHILD) collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity

Authors: HUNTER, KYLIE - University Of Sydney; JOHNSON, BRITTANY - Flinders University; ASKIE, LISA - World Health Organization (WHO) - Switzerland; GOLLEY, REBECCA - Flinders University; Thomson, Jessica

Submitted to: BMJ Open
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2021
Publication Date: 1/20/2022
Citation: Hunter, K.E., Johnson, B.J., Askie, L., Golley, R.K., Thomson, J.L. 2022. Transforming obesity prevention for CHILDren (TOPCHILD) collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity. BMJ Open. 12(1). Article e048166. https://doi.org/10.1136/bmjopen-2020-048166.
DOI: https://doi.org/10.1136/bmjopen-2020-048166

Interpretive Summary: Behavioural interventions conducted in early childhood appear to show some effect for reducing childhood overweight and obesity. While there has been a worldwide increase in very early childhood obesity prevention trials, the effectiveness of such interventions at the population level as well as within specific subpopulations have yet to be determined in a systematic fashion. We present a protocol for a systematic review and meta-analysis using individual participant data to evaluate the effectiveness of obesity prevention interventions beginning prior to or in the first year of birth, and to explore whether there are differential effects among key subpopulations. Systematic searches of Medline, Embase, CENTRAL, CINAHL, PsycInfo, and trial registries for all ongoing and completed randomized controlled trials evaluating behavioral interventions for the prevention of early childhood obesity have been completed up to March 2020 and will be updated annually to include additional trials. Eligible trialists will be asked to share their data. Meta-analyses will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index z-score at age 24 +/- 6 months using World Health Organization Growth Standards. Secondary outcomes include other child weight measures, infant feeding, dietary intake, physical activity, sedentary behaviors, sleep, parenting measures, and adverse events.

Technical Abstract: Behavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of intervention-covariate interactions. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups. Methods and analysis: Systematic searches of Medline, Embase, CENTRAL, CINAHL, PsycInfo, and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2020 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis (PMA) will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index (BMI) z-score at age 24 +/- 6 months using World Health Organisation Growth Standards, and effect differences will be explored among pre-specified individual and trial-level subgroups. Secondary outcomes include other child weight measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events.