lit reviews for the health sciences
DESCRIPTION
Presentation given at the University of Western Ontario as part of the Graduate Student Workshop series on June 21, 2010.TRANSCRIPT
Literature Reviews for the Health Sciences
June 21, 2010Robin FeatherstoneClinical Medicine [email protected] available at: www.slideshare.net/featherr
What’s a Research Lit Review?
A research literature review is a systematic, explicit and reproducible method for identifying, evaluating, and synthesizing the existing body of
completed and recorded work produced by researchers, scholars, and practitioners.*
*Fink, A. (2005). Conducting Research Literature Reviews. London: Sage.
Why would you have to conduct one?
• For your thesis• For your work as a research assistant• For a funding proposal or grant application• For your academic work as a faculty member• For your work as a professional researcher
7 tasks in the Research Lit Review
1. Selecting research questions2. Selecting your sources3. Choosing search terms4. Running your search5. Applying practical screening criteria6. Applying methodological screening criteria7. Synthesizing the results
Selecting research questions
Why do I need a research question?
• To guide your review• To provide you with keywords for your search• To give your research precision
Scenario
You’re applying for a grant to support your research on hygiene in clinical settings.
Think of some specific questions related to this topic...
QuestionsBroad:• What are the best methods of maintaining a
clean clinical environment?
Narrow:• Does hand washing prevent MRSA in the ICU?
Very Narrow:• What are the attitudes of general practitioners in
Southern Ontario to the use of hand washing to prevent MRSA?
How questions influence search results
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
Good Question for Literature Review
Narrow:• Does hand washing prevent MRSA in the ICU?
Selecting your sources
Lit reviews depend on data from seven sources
1. Online public bibliographic databases (i.e., MEDLINE)
2. Private bibliographic databases (i.e., EMBASE)3. Specialized bibliographic databases (i.e.,
Cochrane Database of Systematic Reviews)4. Manual or “hand searches” of references lists5. “Grey literature” -
http://www.slideshare.net/giustinid/libr534-class-vi-ib2
6. Web reports7. Experts
To find databases...
1. Try program pages from the library: www.lib.uwo.ca/programs/
2. Consult your colleagues or your librarian:www.lib.uwo.ca/contact/instruction
Selecting sources
Where are we likely to find articles that answer the question: •Does hand washing prevent MRSA in the ICU?
Some places to search
Bibliographic Databases• Medicine
– PubMed (or Ovid MEDLINE)– EMBASE– Cochrane Library
• Multidisciplinary– Scopus– Web of Science
• Nursing and Allied Health– CINAHL– Proquest Nursing and Allied
Health Source
Web Sources• Associations (APHA) • Organizations (WHO)• Government (MOHLTC, Public
Health Agency of Canada)
Other• “Grey Literature”
– ProQuest Dissertations & Theses, conference proceedings (i.e., AMA), etc...
– BASE Search Engine
Choosing search terms
Breaking down your question
1. Select your database2. Break you question into concepts3. Identify subject headings for each concept4. Identify keywords for each concept
• Tips: – Use a “target article” to help identify search terms– Use a strategy worksheet to keep track of your terms:http://www.lib.uwo.ca/files/taylor/grad/Search_Strategy_Worksheet.pdf
Why do I have to select a database first?
Your database will determine:1. Your subject headings2. Your operators (i.e., truncation symbols)
Different databases have different subject headings
• Tips:– Complete a concept map for each database that you search– Select subject headings that are the closest match for your concept
(remember: systematic, explicit and reproducible)– Pay attention to “explode” commands – some databases will search related
headings by default, others will not
Database Subject Headings
Medline MeSH
EMBASE EMTREE
CINAHL CINAHL Headings
Cochrane Library MeSH
Web of Science N/A
Scopus N/A
Identifying concepts
Which concepts are contained in the question: Does hand washing prevent MRSA in the ICU?
1.Hand washing2.MRSA3.ICU4.Prevention
Concept #1
Sample Search Strategy
Concept #2 Concept #3
Subject Headings
Keywords
AND AND
OR
Hypertension [MeSH]+ Diabetes Mellitus, Type 1 [MeSH]+ Blood Pressure Monitoring, Ambulatory [MeSH]
OR
OR
OR
OR
Hypertensi$.mp. (Diabetes mellitus adj5 (type 1 OR insulin?dependent OR juvenile?onset OR sudden?onset)).mp.
((blood pressure OR BP) adj2 (monitor$ OR test$) adj5 (home OR self OR ambulatory)).mp.
OR
((high OR elevated) adj2 (blood pressure OR BP)).mp.
Iddm.mp.
OR
OR
Some key operators in OvidOperator Command
$ Truncation (finds alternate endings)
? Wildcard (finds alternate spellings)
.mp. Mapping Alias (tells Ovid to search for your term in the Title, Abstract, Subject Headings, Table of Contents and Key Phrase Identifier fields) – useful for lit. reviews because it is broad
() Parentheses control the order of search operations
Adj Adjacency operator (can be followed by a number) tells Ovid terms must appear adjacent to one another
AND all terms must appear in results
OR any terms will appear in results
Note: These are recommended operators for research lit reviews. There are many, many more operators... Use Ovid‘s Help menu to locate them.
Or see: http://content.library.utoronto.ca/gerstein/subjectguides/ovidmedline_shortcuts.pdf
Does hand washing prevent MRSA in the ICU?
Hand washing MRSA ICU Prevention
Running your search
Running your search(es)• Start with your first concept
– Search for the subject headings first– Then search keywords– 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 AND
Running your search(es)
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
Search Ovid MEDLINE
Applying practical & methodological screening criteria
Screening
• Two kinds: practical and methodological • Why?
– Use practical screening to identify a broad range of potentially useful studies
– Use methodological screening to identify the best available studies
Practical Screening Criteria – some examples
1. Date of publication – only studies conducted between 2005 and 2010
2. Participants of subjects – only children 6 to 12 years of age
3. Publication language – only materials written in English
4. Research design – only clinical trials
Methodological Screening Criteria - some questions to ask
• Is the study’s research design internally & externally valid?
• Are the data sources used in the study reliable & valid?
• Are the analytic methods appropriate? • Are the results meaningful in practical &
statistical terms?* *Fink, A. (2005). Conducting Research Literature Reviews. London: Sage.
Applying Screens (or limits)
• Apply practical screens by using “limits” (may also be called “search options”)
• Apply methodological screens by reading through the articles
Apply Practical Screens
• Add the following limit to your combined search result set: – Publication Year: 2000 - Current
Next steps
Moving to another source
• 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 a new concept map
Hand searching and final steps
• Locate the reference lists for selected articles*• Identify new articles that have cited your
articles*• Identify key journals and “hand search” their
issues• Test your search strategy by checking to see if a
few “target articles” appear in the results
* Use Web of Science or Scopus
Working with your results
• Export search results from each database or website into a citation manager (i.e., RefWorks)
• Remove duplicates• Remove inappropriate studies by applying
methodological screens
Synthesizing the results
Look for Patterns
• What conclusions did these studies reach? • Which studies agreed/disagreed with the
consensus?
• Consider using a synthesis matrix:www.ncsu.edu/tutorial_center/writespeak/download/Synthesis.pdf
Use your results to...
1. Describe current knowledge about your research topic
2. Support the need for and significance of new research
3. Explain research findings4. Describe the quality of a body of research*
*Fink, A. (2005). Conducting Research Literature Reviews. London: Sage.
Recap• Remember... research lit review is: systematic, explicit and reproducible• Select appropriate research question• Identify appropriate databases• Break your question into concepts• Identify synonyms and subject headings for each concept • Combine synonym searches with OR • Combine concept searches with AND• Apply practical and methodological screens• Send search results to a citation manager• Remove duplicates• Use your lit review to summarize knowledge, assess research and
support new research initiatives
Questions
Robin FeatherstoneClinical Medicine [email protected]