Evidence mapping: illustrating an emerging methodology to
improve evidence-based practice in youth mental health
Sarah E. Hetrick MA DPsych PGCertHSc,
1
Alexandra G. Parker MPsych PhD,
2
Patrick Callahan PGradDipPsych
3
and Rosemary Purcell MPsych PhD
4
1,2
Research Fellow,
3
Research Assistant,
4
Senior Research Fellow, Centre of Excellence in Youth Mental Health, ORYGEN Research Centre,
The University of Melbourne, Parkville, Victoria, Australia
Keywords
evidence-based practice, evidence mapping,
interventions, knowledge transfer, mental
health, youth
Correspondence
Dr Rosemary Purcell
Centre of Excellence in Youth Mental Health
ORYGEN Research Centre
The University of Melbourne
Locked Bag 10
Parkville Vic. 3052
Australia
E-mail: rpurcell@unimelb.edu.au
Accepted for publication: 13 August 2008
doi:10.1111/j.1365-2753.2008.01112.x
Abstract
Rationale, aims and objectives Within the field of evidence-based practice, a process
termed ‘evidence mapping’ is emerging as a less exhaustive yet systematic and replicable
methodology that allows an understanding of the extent and distribution of evidence in a
broad clinical area, highlighting both what is known and where gaps in evidence exist. This
article describes the general principles of mapping methodology by using illustrations
derived from our experience conducting an evidence map of interventions for youth
mental-health disorders.
Methods Evidence maps are based on an explicit research question relating to the field of
enquiry, which may vary in depth, but should be informed by end-users. The research
question then drives the search for, and collection of, appropriate studies utilizing explicit
and reproducible methods at each stage. This includes clear definition of components of the
research question, development of a thorough and reproducible search strategy, develop-
ment of explicit inclusion and exclusion criteria, and transparent decisions about the level
of information to be obtained from each study.
Discussion Evidence mapping is emerging as a rigorous methodology for gathering and
disseminating up-to-date information to end-users. Thoughtful planning and assessment of
available resources (e.g. staff, time, budget) are required by those applying this methodol-
ogy to their particular field of clinical enquiry given the potential scope of the work. The
needs of the end-user need to be balanced with available resources. Information derived
needs to be effectively communicated, with the uptake of that evidence into clinical practice
the ultimate aim.
Introduction
Evidence-based medicine is defined as the explicit and judicious
use of best available evidence from systematic clinical research in
order to make decisions about the treatment of individual clients
[1]. ‘Best available evidence’ is by no means restricted to system-
atic reviews and meta-analyses, however, in practice, these meth-
odologies have become the ‘gold standard’ for adjudicating the
efficacy, or otherwise, of treatments, given their exhaustive and
rigorous appraisal of primary research, predominantly the results
of randomized controlled trials (RCTs).
Systematic reviews and meta-analyses involve detailed
appraisal of individual RCTs, along with the synthesis of results
across these trials, and therefore provide a high degree of confi-
dence in the consistency and generalizability of research findings
within a circumscribed field of enquiry (e.g. treatment X for con-
dition Y). However, these methodologies are constrained by the
extent to which they are able to provide an indication of the quality
of research evidence within a broader context (e.g. all treatments
for condition Y). A less systematic but nonetheless replicable
process termed ‘mapping’ is an emerging concept that allows
an understanding of the ‘extent, distribution and methodological
quality of research’ relevant to broad topics [2, p. 22]. Evidence
maps aim to identify all relevant literature within a research field in
order to provide a comprehensive assessment of both what is
known and where gaps in evidence exist, with the latter providing
opportunities for new research. The existing evidence can be orga-
nized in ways that relate not only to treatment and management
decisions but also to the organization of clinical services (e.g.
evidence-based health care).
Evidence mapping is in a relatively early stage of development,
and while there is no consensus regarding a mapping metho-
dology, general principles have been articulated, including the
involvement of experts in the field to ensure evidence is relevant
Journal of Evaluation in Clinical Practice ISSN 1356-1294
© 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd, Journal of Evaluation in Clinical Practice 16 (2010) 1025–1030 1025