Large scoping reviews: managing volume and potential chaos in a pool of evidence sources

Scoping reviews can identify a large number of evidence sources. This commentary describes and provides guidance on planning, conducting, and reporting large scoping reviews. This guidance is informed by experts in scoping review methodology, including JBI (formerly Joanna Briggs Institute) Scoping Review Methodology group members, who have also conducted and reported large scoping reviews. We propose a working definition for large scoping reviews that includes approximately 100 sources of evidence but must also consider the volume of data to be extracted, the complexity of the analyses, and purpose. We pose 6 core questions for scoping review authors to consider when planning, developing, conducting, and reporting large scoping reviews. By considering and addressing these questions, scoping review authors might better streamline and manage the conduct and reporting of large scoping reviews from the planning to publishing stage.