[Methods of evidence mapping. A systematic review]

Abstract

Background: Evidence mapping is an increasingly popular approach to systematically evaluate published research. While there are methodological standards for systematic reviews, discrepancies exist between the terminology and methods used within evidence mapping.

Aim: The aim of this systematic review is to describe the methodology and terminology used in evidence mapping and to demonstrate the continuum between evidence mapping and traditional systematic reviews.

Methods: A systematic literature search was conducted in 10 databases in order to obtain a comprehensive picture of the state of the research standards for evidence mapping. In addition, websites of institutions which are already conducting evidence mapping were searched.

Results: The included study pool (n = 12) shows that the terms 'evidence map' and 'scoping review' are widely used within evidence mapping. Evidence maps are an approach to depict both the number and characteristics of studies in tabular form that exist as well as evidence gaps based on primary studies and systematic reviews of broad clinical questions. Scoping reviews also summarize the literature in a tabular form but also give a descriptive narrative summary of the results. A quality assessment of the studies is generally not included.

Conclusion: Evidence mapping allows the identification of research gaps. This aspect is particularly important for interventions which are used without sufficient evidence. In contrast, systematic reviews are mainly used to estimate effects for interventions and evaluate whether the included studies are reliable.