Essential elements required for conducting and structuring an overview of systematic reviews in the field of traditional and complementary medicine

Abstract

Overview methodology, a comparatively new technique, identifies, integrates and updates relevant evidence from multiple systematic reviews (SRs), the unit of analysis being the individual SR. Overviews can help facilitate the translational gap between research and practice. This paper aims to provide a researchers' guide to the structure of an overview by highlighting its essential elements. A narrative literature review was conducted to identify publications on methodology used to conduct overviews of SRs and to provide a synthesis of essential guidance for researchers on the critical steps required. Additionally, examples were identified for analysis and comparison from (T&CM) overview articles published in the European Journal of Integrative Medicine (EuJIM) between 2015 and 2021. Three methodological quality assessment tools were identified and analysed and six published overviews in EuJIM evaluated. Essential elements were identified for inclusion in a T&CM overview. The three key elements highlighted as the most important were; defining a clear aim, detecting overlapping studies and choosing the most appropriate and practical methodological assessment tool. Overviews published in EuJIM demonstrated heterogeneity in the reporting of quality assessment and data synthesis, reflecting the current lack of clear guidance for conducting an overview. This article provides a useful methodological guide highlighting the key items required by researchers wishing to conduct an overview of SRs in T&CM. Note, researchers should be aware that an overview needs to focus on summarizing the best quality existing evidence, but does not provide advice or recommendations on healthcare decision making.