Table 1.

Six principles guiding meta-narrative review^a

Principle	Definition	How we addressed this in the study
Pragmatism	Be guided by what will be most useful to the intended audience	Explicit orientation to MRC stated focus to develop guidance on how to study complex interventions and context using case study methodology
Pluralism	Illuminate the topic from multiple angles	Wide inclusion criteria intended to capture all relevant studies that can be broadly defined as ‘case study’
Historicity	Capture how research traditions have unfolded over time	Consider how later studies drew on, and built on, earlier studies within a tradition, with particular focus on ‘seminal’ (well-regarded, highly-cited) early papers in each tradition
Contestation	Examine ‘conflicting’ data across traditions to generate higher-order insights	Identification and exploration of higher order ‘narrative threads’ (e.g. about what a case study is) being exchanged, contrasting or bridging across the different traditions
Reflexivity	Continually reflect on emerging findings as the review progresses	Regular meetings between team members to share findings and discuss interpretations, including reflecting on how best to produce a useful set of guidance
Peer-review	Present emerging findings to an external audience and use their feedback to guide further reflection and analysis	Delphi panel (currently ongoing) where the findings of this review are presented to a panel of 35 scholars and practitioners for individual scoring, free-text feedback and structured discussion; conference presentations; pilot testing of guidance and meta-narrative review with researchers who have published case studies

^a Adapted from Wong et al. [37]