Innovations in the systematic review of text and opinion

BACKGROUND: Evidence-based healthcare focuses on the need to use interventions that are supported by the best available and most up-to-date evidence or knowledge. Many clinical questions cannot be fully answered by evidence derived from quantitative or qualitative research designs alone, since many areas in healthcare are supported by clinicians' tacit knowledge derived from their clinical experiences. In this situation, evidence generated from a systematic review of text and opinion may be required as the best available evidence. The aim of this study is to highlight the importance and role of expert opinion synthesis in healthcare, and present results of an international methodological group review. METHODS: A methodological group was formed to review this approach, and update the guidance and processes for undertaking a systematic review of text and opinion. RESULTS: The methodology of systematic reviews of text and opinion had already been developed by the Joanna Briggs Institute. We reviewed and updated several steps in the process, such as inclusion criteria, search strategy, critical appraisal and data extraction. CONCLUSIONS: The Joanna Briggs Institute methodology for the systematic review of text and opinion is unique, and continuously evolving and being further developed. Systematic reviews of text and opinion may be considered as legitimate sources of evidence, especially when there is an absence of other research designs.