Challenges of overviews of reviews and how to overcome them, informed by a public health overview

Tags: Oral
Shepherd E1, Middleton P2, Crowther C3
1Robinson Research Institute, University of Adelaide, Australia, 2Robinson Research Institute, University of Adelaide; Health Mothers, Babies and Children, South Australian Health and Medical Research Institute, Australia, 3Robinson Research Institute, University of Adelaide, Australia; Liggins Institute, University of Auckland, New Zealand

Background: Overviews of reviews are a relatively new and innovative method of research synthesis, which can provide a ‘friendly front end’ to the evidence; thus readers do not have to ‘wade through’ or assimilate evidence from separate reviews on different interventions, such as for public health decision-making.

Objectives: To report key challenges associated with conducting an overview of reviews on the effectiveness of interventions for caregiving practices and behaviours for optimal social and emotional development of infants and to propose some solutions.

Methods: Case study of a complex public health overview and analysis of methodological challenges encountered.

Results: The completed overview included 51 systematic reviews (including 11 Cochrane Reviews). Throughout the conduct of the overview, challenges overcome and key considerations related to:

- criteria for inclusion of reviews: deciding on criteria for up-to-datedness of reviews; managing varying definitions and self-identification of reviews as ‘systematic’; priorisiting reviews for inclusion with a question of broad scope;

- assessment of methodological quality of reviews: using AMSTAR and/or ROBIS;

- assessment of the quality of the evidence: applying GRADE to qualitatively and quantitatively pooled review results, including data with no/limited information to assess one or more of the five considerations (study limitations; inconsistency; indirectness; imprecision; publication bias);

- data synthesis and presentation: reporting of single study findings from included reviews; identifying and managing duplication of included studies (and results) within reviews; managing diversity of outcomes, deciding which summary results to present, and how to organise the evidence (such by outcomes or interventions/comparisons).

Conclusions: Though demonstrating potential to accelerate research synthesis for evidence-informed decision-making, overviews come with unique challenges. Further guidance (including Cochrane Handbook expansion and revision) based on methods research and experiential learning will facilitate improved quality and utility. Some suggestions for guidance will be made.