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#robin.featherstone@mcgill.ca

Martin Morris

Bibliothécaire Médical / Medical LibrarianHôpital Royal Victoria Hospital 514-934-1934 ext. 35292martin.morris@muhc.mcgill.ca

Tara Landry

Bibliothécaire médicale / Medical LibrarianMontreal General Hospital 514-934-1934 ext. 43057tara.landry@muhc.mcgill.ca

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)robin.featherstone@mcgill.ca

QuestionsQuestions

Slides: http://www.slideshare.net/featherr