How to Conduct a Systematic Search
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Transcript of How to Conduct a Systematic Search
Robin Featherstone, MLISLiaison Librarian (Medicine)McGill University Life Sciences Library
How to Conduct a Systematic Search
How to Conduct a Systematic Search
ObjectivesObjectives
By the end of today’s class, you will…
1.Be able to conduct a systematic search2.Know who to call for help
A review of a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyse data from the studies
that are included in the review.
From: Cochrane Collaboration (2012). Glossary: Systematic Review. Accessed Jan 6, 2011: http://www.cochrane.org/glossary/5#term423
What’s a Systematic Review?What’s a Systematic Review?
From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi:10.1371/journal.pmed1000097
Flow of Information Through the Different Phases of a Systematic Review
Flow of Information Through the Different Phases of a Systematic Review
Systematic reviews of interventions require a thorough, objective and reproducible search of a
range of sources to identify as many relevant studies as possible (within resource limits).
From: Cochrane Handbook (2012). Section 6: Searching for Studies . Accessed Jan 9, 2011: http://www.cochrane-handbook.org/
What’s a Systematic Search?What’s a Systematic Search?
1. Develop a PICO or research question2. Select sources/database3. Develop a search strategy4. Run the search5. Apply practical screens6. Export references to a citation manager
How to Identify ArticlesHow to Identify Articles
Develop a PICO or Research Question
You’re applying for a grant to support your research on management of patients with atrial fibrillation.
Think of a question related to this topic...
ScenarioScenario
Relevancy
Retrieval(# of search results)
Broad Questions
Narrow Questions
High = lots of articles
Low = very few articles
High = directly relevant articles
Low = mostly irrelevant articles
How questions influence search resultsHow questions influence search results
Broad:• What is the prevalence of post-operative atrial fibrillation?
Narrow:• For cardiac surgery patients with post-operative atrial
fibrillation, do beta-blockers reduce incidents of post-operative stroke?
Very Narrow:• For African Canadian cardiac surgery patients with a history
of diabetes and post-operative atrial fibrillation, does antiplatelet therapy reduce length of hospital stay compared with anticoagulants?
Possible QuestionsPossible Questions
Select Sources/Databases
Article Databases• Medicine
– PubMed, Ovid MEDLINE, EMBASE, Cochrane Library, DARE
• Multidisciplinary– Scopus, Web of Science
• Nursing and Allied Health– CINAHL
• Other– AMED, PsycINFO, Compendex,
Inspec, etc.
“Grey Literature”*• Association, Organization &
Government Reports– Canadian Medical Association,
Health Canada, World Health Organization, etc.
• Conference Proceedings– Embase, Scopus
• Dissertations & Theses– Proquest Dissertations & Theses
Canada
• Web Search Engines– Google Scholar
Where to SearchWhere to Search
* See CADTH checklist: http://cadth.ca/en/resources/grey-matters
1. What is the optimum withdrawal time during colonoscopy to screen for adenomas and polyps?
A. MEDLINE
2. What are proven methods for integrating simulators into endoscopy training?
B. PsycINFO
3. When should patients presenting with febrile neutropenia to the Emergency Department be administered antibiotics?
C. Inspec
4. Which injection method is the most effective for administering lidocaine?
D. EMBASE
5. Which factors improve quality of life for patients post mastectomy?
E. SCOPUS
6. What is the analgesic efficacy for antipsychotic agents for chronic pain?
F. Cochrane Library
Match the Question to the Source(s)Match the Question to the Source(s)
Develop a Search Strategy
1. Select your database2. Break you question into concepts3. Identify subject headings for each concept4. Identify text words for each concept
• Tips: – Use a “target article” to help identify search terms– Use a worksheet to keep track of your terms
Step-by-StepStep-by-Step
Which concepts are contained in the question:
Does hydration decrease incidence of delirium at the end of life?
Identify ConceptsIdentify Concepts
What is MeSH?
Tips:– Select subject headings that are the closest match for your
concepts– Pay attention to “explode” commands – PubMed will search
related headings by default
Database Subject Headings
Medline/PubMed MeSH
EMBASE EMTREE
CINAHL CINAHL Headings
Cochrane Library MeSH
PsycINFO Thesaurus of Psychological Index Terms
Scopus, Web of Science N/A
Subject HeadingsSubject Headings
A. Bird Diseases B. Neutropenia
Which Subject Heading Explodes?Which Subject Heading Explodes?
What are MeSH headings for these concepts?
Add appropriate subject headings to your worksheet
Identify Subject HeadingsIdentify Subject Headings
Hydration Delirium End of Life
AND AND
OR exp Fluid Therapy/ Delirium/ exp Terminal Care/
OR Palliative Care/
exp Terminally Ill/
OR
OR
OR
Concept #1 Concept #2 Concept #3
Subject Headings
TextWords
Blank worksheets: http://www.slideshare.net/featherr/search-strategy-worksheet
Ovid Medline StrategyOvid Medline Strategy
Why? 1.Not all citations have subject headings
Next: Identify Text WordsNext: Identify Text Words
Image credit: http://cdn.zmescience.com/wp-content/uploads/2011/09/cyborg.jpg
2. Indexers are only cyborgs
Operator Command Example
* Find alternate endings hosp* [will find hospital, hospitals, hospitalist, hospice, hospices, etc.]
.tw. Search for this term in the Title and Abstract fields
anxiety.tw.
adj Search for one term within x number of terms from another
patient adj3 anxiety [will find patient within three words of anxiety]
AND Find articles where both terms appear
smoking AND cessation
OR Find articles where either term appears
smoking OR tobacco
() Control order of operations – commands within brackets run first
(smok* OR tobacco).tw.
Ovid Search Commands for Text Word SearchingOvid Search Commands for Text Word Searching
AND AND
OR exp Fluid Therapy/ Delirium/ exp Terminal Care/
OR Palliative Care/
exp Terminally Ill/
OR
hydrat*.tw. deliri*.tw. (terminal* adj4 patient*).tw.
OR
fluid*.tw. palliative.tw.
ORwater.tw. end of life.tw.
Concept #1 Concept #2 Concept #3
Subject Headings
TextWords
Ovid Search StrategyOvid Search Strategy
#7) Describe all information sources (e.g. databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.
#8) Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.
PRISMA Checklist for Reporting Systematic ReviewsPRISMA Checklist for Reporting Systematic Reviews
From: PRISMA Statement for Reporting Systematic Reviews (2012). PRISMA Checklist. Accessed Jan 10, 2011: http://www.prisma-statement.org/
BREAK – 10 mins
Run the search
• Start with your first concept– Search for the subject headings first– Then search text words– Combine these synonymous searches with OR using
your search history
• Repeat for your second, third, and subsequent concepts
• Finally, combine large search results set with ANDTip: Test your search strategy by checking to see if a few “target
articles” appear in the results
How to SearchHow to Search
Search #2 =
Search #3 =
Search #4 =
Search #5 = #1 OR #2 OR #3 OR #4
Search #1 =
Concept 1
Search #6 =
Search #7 =
Search #8 =
Search #9 =
Concept 2
Search #10 = #6 OR #7 OR #8 OR #9
Search #11 = #5 AND #10
Results
How to SearchHow to Search
AND AND
OR exp Fluid Therapy/ Delirium/ exp Terminal Care/
OR Palliative Care/
exp Terminally Ill/
OR
hydrat*.tw. deliri*.tw. (terminal* adj4 patient*).tw.
OR
fluid*.tw. palliative.tw.
ORwater.tw. end of life.tw.
Concept #1 Concept #2 Concept #3
Subject Headings
TextWords
Demo
Applying practical screening criteria
Two kinds:
1. Practical screens identify potentially useful studies
2. Methodological screens identify best available studies
ScreeningScreening
1. Date of publication – only studies conducted between 2005 and 2010
2. Participants or subjects – only children 6 to 12 years of age
3. Publication language – only materials written in English or French
4. Research design – only clinical trials
Practical Screens/Limits ExamplesPractical Screens/Limits Examples
Apply to your combined search result set:
– English & French Language– Publication Year: 2001 – Current
Apply Screens/LimitsApply Screens/Limits
Export References to a Citation Manager
Available to McGill students, faculty, staff.
Download from: http://mcgill.e-academy.com/
What they do:– Identify and remove duplicate references– Format your bibliography– Organize references into folders– Share your references with colleagues– Automatically find full-text articles
Information and workshops: http://www.mcgill.ca/library/library-using/endnote/help/
Citation ManagersCitation Managers
Next steps
• Retain as much of your original strategy as possible
• Recognize that subject headings will be different (or non-existent)
• Keep track of your search terms using new worksheets
Moving to Another SourceMoving to Another Source
• Locate the reference lists for selected studies*• Identify new articles that have cited your
studies*• Identify key journals and “hand search” their
issues• Contact study authors
* Use Web of Science or Scopus
Hand SearchingHand Searching
From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi:10.1371/journal.pmed1000097
Next stepsNext steps
• How would you describe a systematic search?
• Synonymous searches are combined with ___
• Can you apply methodological screens with a database?
RecapRecap
Where to go for HelpWhere to go for Help
Robin Featherstone
Liaison Librarian (Medicine)Life Sciences Library, McGill University 514-398-4475 ext. 09844#[email protected]
Martin Morris
Bibliothécaire Médical / Medical LibrarianHôpital Royal Victoria Hospital 514-934-1934 ext. [email protected]
Tara Landry
Bibliothécaire médicale / Medical LibrarianMontreal General Hospital 514-934-1934 ext. [email protected]
ResourcesResourcesSystematic review guidelines:Cochrane Handbook for Systematic Reviews of Interventions http://www.cochrane-handbook.org/PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-Analyses) http://www.prisma-statement.org/statement.htm Systematic Reviews: CRD’s Guidance for Undertaking Reviews in Health Carehttp://www.york.ac.uk/inst/crd/SysRev/!SSL!/WebHelp/SysRev3.htm IOM (Institute of Medicine). Finding what works in health care: standards for systematic reviewshttp://www.iom.edu/Reports/2011/Finding-What-Works-in-Health-Care-Standards-for-Systematic-Reviews.aspx
Searching for grey literature:CADTH (Canadian Agency for Drugs and Technologies in Health). Grey Matters: a practical search tool for evidence-based medicine http://cadth.ca/resources/grey-matters
Citation management:Getting help with EndNotehttp://www.mcgill.ca/library/library-using/endnote/help/
Robin Featherstone, MLISLiaison Librarian (Medicine)[email protected]
QuestionsQuestions
Slides: http://www.slideshare.net/featherr