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Systematic Reviews - Part II

John Galejohn.r.gale@kcl.ac.ukInformation Specialist – Institute of Psychiatry

Sonya Lipczynskasonya.lipczynska@kcl.ac.uk Information Specialist - Dentistry & Physiotherapy

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Introduction

• More advanced search techniques using Ovid databases

• Reading a search strategy• Grey literature: dissertations, conference

proceedings, Government reports, unpublished trials etc

• Selecting studies to include in your review• Documenting your search• Where to go to get extra help/find out more

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An example of a search strategy

http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006911.pub2/abstract

(navigate to Appendices for search strategy via ‘Jump to’ box under Article tab).

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Practical exercise

• Truncation – behavio* therapy• Wildcard searching – p?ediatrics• Adjacency searching – acute adj5 otitis media• Boolean operators – AND/OR/NOT• Floating sub-headings• Limiting to fields – PT, TW, AB• Subject headings vs free-text searching

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Sources of published search strategies – for some or all of your search concepts• Cochrane Library

– Cochrane Reviews: Cochrane Database of Systematic Reviews (Appendix or review)

– Other Reviews: Database of Abstracts of Reviews of Effect

• Campbell Collaboration – produce systematic reviews in education, crime and justice,

and social welfare (Appendix or review)

• Other published systematic reviews– Possibly online only in an appendix (may not be in pdf

version)– Evaluate the quality – can you do better?

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Peer review of search strategies• Mcgowan, J., Sampson, M., Lefebvre, C.. An Evidence

Based Checklist for the Peer Review of Electronic Search Strategies (PRESS EBC). Evidence Based Library and Information Practice, North America, 5, Mar. 2010. Available at: < https://ejournals.library.ualberta.ca/index.php/EBLIP/article/view/7402/6436>. Date accessed: 30 Aug. 2012.

• PRESS EBC can be used to assess your own search strategy as well as those of systematic reviews you are reading or thinking of making part of your own strategy.

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Using Filters

• Cochrane filter for RCTs– http://handbook.cochrane.org/ (section 6.4.11)

• SIGN – http://www.sign.ac.uk/methodology/filters.html

• Centre for Reviews and Dissemination – http://www.york.ac.uk/inst/crd/intertasc/rct.htm

• National Clinical Guideline Centre– http://www.ncgc.ac.uk/Guidelines/

(navigate to appendix of specific guideline)• McMaster University Hedges Project

– http://hiru.mcmaster.ca/hiru/HIRU_Hedges_home.aspx

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Grey Literature

“There are many definitions of grey literature, but it is usually taken to mean literature that is not formally published in sources such as books or journal articles.” (Cochrane Handbook, 2011)

Examples of grey literature include:• Technical or research reports from government agencies • Reports from scientific research groups• Working papers from research groups or committees• Doctoral dissertations• Some conference proceedings and official publications

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Publication bias

Papers with more ‘interesting’ results are more likely to be:

• Submitted for publication• Accepted for publication• Published in a major journal• Published in the English language• Publication bias and outcome reporting bias:

agomelatine as a case example. Howland, R. H. Journal of Psychoscocial Nursing and Mental Health Services 49(9), September 2011

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Searching grey literature I

• openGrey (System for Information on Grey Literature) http://www.opengrey.eu/

• Libraries of specialist research organisations and professional societies

• Very useful guide produced by the Canadian Agency for Drugs and Technologies in Health (CADTH) available here

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Searching grey literature II

• HMIC (The Healthcare Management Information Consortium) – DH and King’s Fund – via Databases list (King’s username and password)• DH publications including: circulars and press

releases• King’s Fund research on health and community,

care management, organizational development, inequalities in health, user involvement, race and health

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Searching grey literature III

• www.opendoar.org Directory of Open-Access repositories. Cross-searches the open-access repositories of 1000s of universities, world-wide. Many references contain full-text working papers alongside references to journal articles, these and reports. Full-text available where copyright allows

• Social Science Research Network http://www.ssrn.com/

451,800 abstracts and 365,700 full-text docs. Subject-specific networks, including one for health

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Trials Registers

Metaregisters of Controlled Trials – which bring together several international sources

• The IFPMA clinical trial portal• The International Standard Randomised Controlled Tr

ial Number (ISRCTN) register• The WHO International Clinical Trials registry• US register of clinical trials• Other resources available in the Cochrane Handbook

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Conference Proceedings

Need to try and get full-text if possible

Can be found on:• Medline – search for Congresses and then combine

with a topic using AND• Web of Science• SciVerse Scopus

Access all of these from the Library Services database list

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Theses and Dissertations

• Some Ovid databases e.g. CINAHL and PsycInfo include dissertations

• WorldCat dissertations and Theses (OCLC) can be accessed via King’s databases page

• Senate House – Index to Theses in Great Britain and Ireland covers >500,000 theses

• British Library’s eThos site – http://ethos.bl.uk • Scirus – you can use the Advanced Search to search

just for theses and dissertations

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Handsearching

Physically searching the contents of journals, conference proceedings and abstracts page by page

• Can identify articles not yet included in electronic databases

• Articles or studies not indexed properly

BUT it’s impossible to search all journals so prioritise using the results of your searches of databases such as MEDLINE, EMBASE etc

You can also use the reference lists of papers you have found earlier

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Direct Contact

• Making direct contact – usually by email – with the authors or organisations who are experts in this field

• Authors often include their contact details in abstracts• Can find out about ongoing or unpublished research• Papers not on your list which authors might be aware

of

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Relevant internet resources

This does NOT mean Google or Google Scholar!

Look at specific relevant websites aimed at a particular topic or subject search engines:

• Royal College and Society webpages for reports and guidance

• NICE Evidence Search - http://www.evidence.nhs.uk/ – NHS search engine to locate evidence in health and

social care.• TRIP database http://www.tripdatabase.com/

– clinical search tool to identify the highest quality clinical evidence for clinical practice.

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Selecting studies and managing references• Merge and de-duplicate search results using

bibliographic software (make a copy of de-duped)• Examine title and abstracts• Best practice to retain evidence of what articles have

been excluded (and potentially why)• Retrieve full text of potentially relevant articles• Link together multiple reports

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How much is enough?

• Funding/time– A broad search topic or searching more

databases/resources etc all increases the amount of time required to sift results. No set timescale – depends on your circumstances and any funding restrictions

• Focusing on RCTs/observational studies– Widening a SR to include observational studies is likely to

increase the number of results you have to sift through.

• Personal/team knowledge – are all key known papers in your subject area retrieved in the search?– Amend search if not/include further databases – you would

expect key papers to be returned by a successful search strategy if indexed in the databases you are searching.

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Inclusion/Exclusion Criteria• Randomised Controlled Trials (RCTs) usually seen as

the gold standard [e.g. required for Cochrane SRs on interventions if possible]– This not always possible e.g. Interventions on pregnant

women

• How big was the trial? – Will you only include trials with >5; >10; >50; >100 active

participants?

• Double-blind?

• Compared to placebo, waiting list or another treatment?

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Study flow diagramsFlow diagram should present the number of:• unique records identified by the searches• records excluded after preliminary screening (e.g. of titles and

abstracts)• records retrieved in full text• records or studies excluded after assessment of full text• studies meeting eligibility criteria for the review• studies contributing to the main outcome • check lists and flow diagrams available from the

PRISMA web site

(PRISMA, 2009)

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Documenting your search: Why?

This is crucial because:• It forms a vital part of the systematic review in its own

right• Your searches should be able to be evaluated by

other researchers and reproduced in the future

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Documenting your search: What you need to record• Information about the databases and interfaces searched

including dates covered and when you did your search• Full, detailed search strategies (copied and pasted) and the

number of records retrieved• Details of other searches including conference proceedings,

handsearching, contact with experts, reference lists and citation searching and internet searching

• You’ll also need to specify the criteria you use to select trials – beyond the scope of this course!

• There are examples at • http://www.york.ac.uk/inst/crd/pdf/Systematic_Reviews.pdf

[Appendix 2]

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Reporting Guidelines and Evaluation tools• Equator Network: overview of reporting

guidelines. Links to:– Consolidated Standards Of Reporting Trials -

CONSORT website: http://www.consort-statement.org/

– Preferred Reporting Items for Systematic Reviews and Meta-Analyses – PRISMA website: www.prisma-statement.org

– Meta-analyses of observational studies – MOOSE - article and proposed reporting checklist available at PMID: 10789670

• Critical Appraisal Skills Programme http://www.casp-uk.net/

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External Resources

• CRD’s Guidance for undertaking reviews in healthcare

http://www.york.ac.uk/inst/crd/index_guidance.htm• Cochrane Handbook (for systematic reviewers)

http://www.cochrane-handbook.org/

http://training.cochrane.org/• Intertasc – search filter resource

www.york.ac.uk/inst/crd/intertasc/

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EndNote courses

• Keep an eye out on Skills Forge https://training.kcl.ac.uk

• 1:1s available with your Information Specialist whose contact details you can find at: www.kcl.ac.uk/library/contact/spec/specialists.aspx

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Further information and supportLibrary Services’ Searching for Literature guide

• User guides on specific interfaces and databases available at http://www.kcl.ac.uk/library/help/guides.aspx

• Contact your school’s Information Specialist at http://www.kcl.ac.uk/library/contact/spec/specialists.aspx

• EndNote pages at http://www.kcl.ac.uk/library/help/bibsoftware/endnote/index.aspx

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Online evaluation form https://internal.kcl.ac.uk/it/training/Course-evaluation/index.aspx

Go to the Internal King’s webpage• Click on the IT Services icon• Click Training from the left hand menu • Click on the link to Course Evaluation on the left hand menu• Click Information skills course evaluation • Select today’s date for the LIB212 Enhancing skills for systematic reviews Part 2

course and fill in the online form