Understanding effectiveness, intervention complexity and endusers experiences in rapid infant weight gain prevention: A systematic review and metaanalysis

Introduction: Rapid infant weight gain (RIWG) has repeatedly been identified as a strong risk factor for childhood overweight and obesity (COO) and has therefore been given increasing attention as a target for early life COO prevention. However, no attempts have yet been made to review this evidence. Furthermore, despite few previous studies on COO prevention being found very effective,
little work has been conducted in order to understand the lack of effectiveness. The aim of this study is therefore threefold: 1) to evaluate intervention effectiveness, 2) to attain in-depth understanding of intervention
components, and 3) to understand end-users experiences in intervention involvement.
Material and methods: This review is registered in PROSPERO (CRD42018076214). PubMed, EMBASE and several other databases were searched in order to identify relevant published and unpublished quantitative and qualitative evidence. Eligible quantitative studies reported on interventions that defined RIWG using weight-for-age z-scores in infants aged 0-2 years. Qualitative studies reported on end-users experiences on involvement in
relevant interventions. Cochrane risk of bias tool, ROBINS-I and EPPI-centre tool was used to critical appraise quantitative and qualitative studies, respectively. A meta-analysis, an intervention component analysis (ICA) and a thematic analysis on end-users experiences are being conducted based on the included papers.
The ICA is being conducted by combining evidence of effectiveness with evidence from relevant qualitative studies, as well as with more informal evidence, such as accounts reported by researchers in discussion sections.
Results: Seven quantitative studies and six qualitative studies were eligible for inclusion. Preliminary results from the meta-analysis shows pooled intervention effects on mean changes in weight-for-age z-scores between 0-6 and 0-12 months of age. Further analyses are currently being conducted.
Conclusions: The utilization of multiple methods of analysis in this review can support development of more comprehensive evidence on early life prevention of RIWG and COO. Furthermore, the review results may, when informed by the ICA, ease decision-making and implementation in policy and practice in this
area of prevention, as the aim of an ICA is to highlight which intervention components to take forward in which contexts in order to improve the effectiveness of health services.