Mapping Reviews, Scoping Reviews and Evidence and Gap Maps (EGMs) – Same but Different. The ‘Big Picture’ Review Family
2University of Toronto in the Dalla Lana School of Public Health & Institute of Health Policy, Management, and Evaluation, Canada
3University of Adelaide, Australia
4Campbell Collaboration, India
5University of Sheffield, United Kingdom
6Global Development Network, India
7La Trobe University, Australia
Background: Scoping reviews, mapping reviews and evidence and gap maps (EGMs) are evidence synthesis methodologies that address broad research questions, aiming to describe a bigger picture rather than address a specific question about intervention effectiveness. They are being increasingly used to support a range of purposes including guiding research priorities and decision-making. There is, however, a confusing array of terminology used to describe these different approaches.
Objectives: In this commentary we aim to describe where there are differences in terminology and where this equates to differences in meaning. We demonstrate the different theoretical routes that underpin these differences. We suggest ways in which the approaches of scoping and mapping reviews may differ in order to guide consistency in reporting and method.
Methods: We undertook a critical analysis of the methods and cited methods used in published scoping, mapping and EGM reviews and guidance.
Results: Scoping reviews, mapping reviews and evidence maps are terms that are not used consistently within the literature, with different terms used to describe similar approaches and review objectives and sometimes the same term is used to describe different approaches. We show the scientific traditions that have shaped these approaches. Scoping reviews tend to have a more focused question and data extraction and analysis is richer than in mapping reviews and EGMs. EGMs have a unique place within the range of evidence synthesis approaches for greater transparency in identifying gaps in the evidence. EGMs are visual and interactive web-based tools. We propose that mapping and scoping reviews and EGMs have similarities that unite them as a group but with their unique differences. The accompanying graphic summarises these differences (Figure 1).
Conclusions: Understanding these similarities and differences is important for informing the development of methods used to undertake and report these types of evidence synthesis. We hope this work will help to improve consistency in description and reporting.
Patient, public and/or healthcare consumer involvement: None.