Table 5 Tools for narrative synthesis and risk of bias

2

Evans et al. (2002)—the synthesis process/tabulation

A textual summary of the results in a tabular format with headings such as setting, participants, research aim, sampling technique, analysis and results.

2

Clarke and Braun (2006, 2013)—thematic analysis

The data presented in tabular format will allow papers to be grouped according to themes that appear between and within studies. Themes may relate to particular features such as dietary intervention, stakeholder groups or main findings. Recurrent themes will be analysed using thematic analysis.

3

Popay et al. (2006)—Narrative synthesis/investigate heterogeneity/conceptual mapping

Identify and investigate key characteristics that vary between the studies in order to elucidate the different findings.

Clinkenbeard (1991)—Idea map or spider diagram

Explore connections reported across the studies.

4

Popay et al. (2006)—Robustness of the synthesis

Lincoln and Guba (1985) [52]—Assessment of bias

Critical reflection will focus on (1) identifying study limitations and its impact on the findings; (2) risk of bias (quality, validity and generalisability (for quantitative research) and a focus on confirmability, transferability, credibility and trustworthiness (for qualitative research); (3) differences and uncertainties in the findings and how addressed; (4) identify aspects of the research where the evidence is weak or absent; (5) suggestions for future research and lastly; (6) the evidence will be synthesised and presented to highlight the ‘thick’ and ‘thin’ findings, key differences and strengths.