Methods of evidence mapping: a systematic review

Article type
Authors
Schmucker C1, Motschall E2, Antes G1, Meerpohl J1
1German Cochrane Center, Germany
2Institute of Medical Biometry and Statistics, University Medical Center Freiburg, Germany
Abstract
Background:
Evidence mapping is an increasingly popular approach for the systematic evaluation of published research. While there are clear methodological standards for systematic reviews, variability exist between the terminology and methods used within evidence mapping.

Objectives:
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 for methodological studies was conducted in 10 databases in order to obtain a comprehensive picture of the state of research standards for evidence mapping. In addition, websites of institutions that are 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 the field of evidence mapping. Evidence maps are an approach to depict both the number and characteristics of studies that exist in tabular form, 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, in addition, 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 that 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.