Knowledge synthesis methods for generating or refining theory: a scoping review reveals that little guidance is available

Objectives: To describe and compare, through a scoping review, emerging knowledge synthesis methods for generating and refining theory, in terms of expertise required, similarities, differences, strengths, limitations, and steps involved in using the methods. Study Design and Setting: Electronic databases (e.g., MEDLINE) were searched, and two reviewers independently selected studies and abstracted data for qualitative analysis. Results: In total, 287 articles reporting nine knowledge synthesis methods (concept synthesis, critical interpretive synthesis, integrative review, meta-ethnography, meta-interpretation, meta-study, meta-synthesis, narrative synthesis, and realist review) were included after screening of 17,962 citations and 1,010 full-text articles. Strengths of the methods included comprehensive synthesis providing rich contextual data and suitability for identifying gaps in the literature, informing policy, aiding in clinical decisions, addressing complex research questions, and synthesizing patient preferences, beliefs, and values. However, many of the methods were highly subjective and not reproducible. For integrative review, meta-ethnography, and realist review, guidance was provided on all steps of the review process, whereas meta-synthesis had guidance on the fewest number of steps. Conclusion: Guidance for conducting the steps was often vague and sometimes absent. Further work is needed to provide direction on operationalizing these methods.The study was funded by a Canadian Institutes of Health Research (CIHR, grant number: ​KST-116633) Knowledge Synthesis grant