PROSPERO
International prospective register of
systematic reviews
An overview of development and progress
May 2013
Centre for Reviews and Dissemination
Background: the need for registration
• Systematic reviews usually provide the evidence base
upon which health and social care decisions are made
so they should be robust and free from bias
• There is concern about publication and selective
outcome reporting biases associated with systematic
reviews
• Unplanned duplication of reviews is a waste of resource
– No open register for review protocols (Cochrane and Campbell
Collaboration protocol registration limited to their own
organisations)
• PRISMA 2009 Checklist: asks for protocol and
registration details
Centre for Reviews and Dissemination
Taking the initiative
• Following publication of the PRISMA statement CRD
began to receive unsolicited requests to register
systematic reviews
• CRD has an established IT platform and infrastructure
for the DARE, NHS EED and HTA databases
• Set up an international advisory group
• Carried out an international consultation to establish a
minimum dataset and raise awareness
Centre for Reviews and Dissemination
Registration minimum dataset 22 required fields:
Administrative
Review design
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Review title
Named contact(s)
Contact e-mail
Organisational affiliation
Funding source/sponsors
Conflict of interests
Anticipated or actual start date
Stage of review†
Anticipated completion date
Review status†
† these fields are updated as the review progresses
Centre for Reviews and Dissemination
Review question/objective
Condition/domain studied
Search details
Participants/population
Intervention/exposure
Comparator/control
Study types
Primary outcomes
Secondary outcomes
Risk of bias (quality) assessment
Strategy for data synthesis
Planned subgroup analyses
Registration dataset 18 optional fields:
Administrative
Review design
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Contact postal address
Contact phone number
Review team members & affiliations
Collaborators
Other registration details
Organisational reference number
Language
Country
Key words
Existing review by same authors
Any other information ‡
Centre for Reviews and Dissemination
Type of review
URL to search strategy
URL to full protocol‡
Context
Data extraction methods
Dissemination plan
Link to final report/publication ‡ (added
over time)
‡ Fields included in response to Delphi comments
PROSPERO:
International prospective register of systematic
reviews
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Web based
Free to register
Free to search
Users create and update their own records
Minimum data set required
Record content is the responsibility of review lead
Administrators check for “sense” not peer review
A public audit trail of amendments is maintained
Centre for Reviews and Dissemination
Eligibility for inclusion in PROSPERO
• Systematic reviews of the effects of interventions and strategies to
prevent, diagnose, treat, and monitor health conditions, for which
there is a health related outcome
• Reviews of methodological issues need to contain at least one
outcome of direct patient or clinical relevance in order to be included
in PROSPERO (included from November 2012)
• Systematic reviews of reviews with a health related outcome
(included from November 2012)
• New Cochrane review protocols uploaded automatically (should not
be registered individually) (included from Jan 2013)
• Registration should take place once the systematic review protocol
is finalised, but ideally before screening studies for inclusion begins
Centre for Reviews and Dissemination
Eligibility for inclusion in PROSPERO
• Exclusions:
– Scoping reviews
– reviews of animal studies
– reviews of methods for which there is no direct
health related outcome
• Reviews that have progressed beyond the
completion of data extraction are not accepted
• Completed reviews are not accepted
Centre for Reviews and Dissemination
The story so far…
PROSPERO opened for registration 22 February 2011
In April 2013:
• Registered reviews being undertaken in 57 different
countries
• 1467 registrations published:
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1245 are ongoing reviews
167 are completed but not yet published
62 are completed and published
6 have been abandoned
Centre for Reviews and Dissemination
Cumulative new registrations on PROSPERO
1600
1486
1365
1400
1255
1155
1200
1045
974
1000
897
813
800
738
680
551
600
400
200
0
11
25
40
81
109 134
170
202
240
285
0
Centre for Reviews and Dissemination
322
372
423
472
599
Supporters of the principle of registration
and PROSPERO
• Organisations and networks
– NIHR, CIHR, Cochrane and Campbell Collaborations, Joanna
Briggs Institute, INAHTA, Guidelines International Network,
James Lind Alliance, ANZCTR, WHO Alliance for Health Policy
and Systems Research, AZQ, Public Health Wales, HNODS
• Publishers
– PLoS journals, BMJ, BMJ Open, BioMed Central, BJOG:
recommend registration in their instructions to authors
• Funders
– The UK NIHR have introduced mandatory registration for all the
eligible systematic reviews they fund
Centre for Reviews and Dissemination
Achieving aims
• Reduce unplanned duplication of reviews:
– the NIHR HTA Programme decided not to commission
research on restricted elimination diet in Attention DeficitHyperactivity Disorder after finding on PROSPERO an
overlapping research project already in progress
• Allow comparison of plans with final report:
– PROSPERO registration number now appearing in final
reports in peer reviewed journals
– Peer reviewers are contacting CRD with queries, in
particular about stage of review at time of acceptance
Centre for Reviews and Dissemination
Evaluation of utility at one year
Administrative data and web statistics were
collated and an online survey of users’
experiences undertaken:
• Registration is feasible and not overly
burdensome
• On the whole, survey respondents are satisfied
- the system allows registration in a
straightforward and acceptable way
• Some changes introduced to improve user
experience e.g. save draft as editable document
Centre for Reviews and Dissemination
Future developments
• Encourage more supporters to help raise awareness
of the value of prospective registration of systematic
reviews
• Work with commissioning and funding organisations
to help facilitate grant holder uptake and compliance
• Continue to broaden the inclusion criteria
• Promote the wide use of both the registration
process and the search facility
• Conduct methodological research
Centre for Reviews and Dissemination
The development and ongoing management of PROSPERO is supported by
CRD’s core work programme which is funded by the National Institute for Health
Research, England; the Department of Health, Public Health Agency, Northern
Ireland and the National Institute for Social Care and Health Research, Welsh
Government
The views expressed are those of the author(s) and not necessarily those of the
NHS, NIHR, Department of Health, or any of CRD’s funders
www.crd.york.ac.uk/PROSPERO
Centre for Reviews and Dissemination