Chapter 2 medical literature search process

1. Chapter 2
Dr. saroj suwal

2.  What is medical literature search
 Why search
 For whom search
 Steps in searching
 Quality searching

3. an activity that uses professional methods
for medical research papers retrieval, report
and other data to improve medicine research
and practice.

4. Literature search:
Right path to the right
reference

5.  For writing thesis,review ,jornals ,reports etc
 For working as a research assistant
 For finding funding proposal or grant application
 For academic work as a faculty member
 For working as a professional researcher

6.  Searching the literature is an essential component
of the scholarly research process
 to conduct a quality literature search  crucial for
academic study and professional development
 to create and publish secondary analysis on a specific
topic,
 for analysis of original research,
 to be able to locate the best evidence to answer
clinical questions

7. Broad search question
specificvSearch results
Relevant
Search results
Your specific search resutl

8. Qualitative Studies

9.  Searchosteoarthritis of the knee.
 13,886 articles in PubMed
 Search RCTs on arthroscopic surgery for
osteoarthritis of the knee that include placebo
surgery as a control.
 9 articles in PubMed
 SearchRCTs on arthroscopic surgery conducted
in latino females with type 1 diabetes mellitus.
 0 articles in PubMed

10. 1. Develop a search statement or question
2. Select a source
3. Choose search terms
4. Run the search
5. Apply practical screens (limits)
6. Apply methodological screens
7. Synthesize the results

11. WHY?
 To guide your review
 To provide you with keywords for your search
 To give your research precision
1. Developing search questions

13. “FINER”
F= Feasible
I= Interesting
N= Novel
E= Ethical
R= Relevant

14. Broad:
• What is the prevalence of hypertension in patients with diabetes mellitus?
Narrow:
• Does ambulatory BP readings improve detection rates for hypertension in
patients with type 1 diabetes mellitus?
Very Narrow:
• What are the attitudes of general practitioners in south china to the use of
ambulatory BP readings for patients with type 1 diabetes mellitus?

15. 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

17. The PICO format:
P Population
I Intervention or Interest area
C Comparison intervention or status
O Outcome

19.  Internet Websites, search engines, news & alert services
 The Library
 Look through the list of journals and browse the text books on
the shelves to find relevant ones
 Digital Libraries
 Need to use keyword searches to identify relevant articles
 Newspaper and magazines
 Text books, Guidelines, Factsheets, Databases,
Reports

20. Primary Source-original
journals
Secondary Source –review
articles
Tertiary Source-text books

21. Web Sites
 can be very good for finding quality information
including primary sources, statistical information
and many more
 rigorously evaluate each site for quality and
responsibility
 Because anyone can post a Web page, regardless of
their expertise or intentions.
 Use keyword searches in Google (which indexes PDF and
PostScript academic publications)

22. Search Engines
General Web search engines :
Google, AllTheWeb and Yahoo,baidu, altavista….
For research covered only in unpublished reports or news items, this might be the best method
of locating that information. Among the most popular search engines are:
 Google http://www.google.com ,AlltheWeb http://www.alltheweb.com
 Yahoo http://www.yahoo.com,
 MSN Search http://search.msn.com
 Bai du Search www.baidu.com

24. Professional medical search engine
PubMed
GoPubMed
Pubget
eTBLAST
Cochrane Reviews, The Cochrane Library
Healia
Medical search engines

25.  Trip
 NLM Gateway
 Entrez, NLM's cross-database search
 SUMSearch

26.  MedlinePlus by the U.S. NLM
 Healthfinder by the U.S. HHS
 Mednar
 Healthline
 Medstory

27. Bibliographic Databases
 Medicine
 PubMed (or Ovid MEDLINE), EMBASE, Cochrane Library
 Multidisciplinary
 Scopus
 Web of Science
 Nursing and Allied Health
 CINAHL
Websites
 Associations, Organizations & Government
 WHO, American Diabetes Association, Canadian Diabetes Association, Health
Canada, Public Health Agency Canada etc...
Other
 “Grey Literature”
 ProQuest Dissertations & Theses, conference proceedings (i.e., AMA), etc...

28. News and Alerting Services
Government Sources Press Releases, Fact Sheets,
Newsletters
 CDC "In the News" -
http://www.cdc.gov/od/oc/media/
 NIH News and Events - http://www.nih.gov/news/
 FDA New and Generic Drug Approval -
http://www.fda.gov/cder/approval/index.htm
 FDA Medical Products Reporting -
http://www.fda.gov/medwatch/index.html

30. •AMA News - http://www.ama-
assn.org/public/journals/amnews/amnews.htm
•Yahoo Health News -
http://dailynews.yahoo.com/headlines/health/
•Reuters Health http://www.reutershealth.com

32. 1. Select your database
2. Break you question into concepts
3. Identify subject headings for each concept
4. Identify keywords for each concept
Tips:
 Use a “target article” to help identify
search terms
 Use a concept map to keep track of your
terms

33. Database Password?
High quality evidence only!
NHS Evidence www.evidence.nhs.uk(no password)
TRIP database
www.tripdatabase.com
(no password)
Cochrane Library
www.thecochranelibrary.com
(no password)
Great General Databases
PubMed (Medline)
www.pubmed.gov(no password)
Use this version of PubMed to
see reliable links to Cambridge journals
or Available via NHS ATHENS
Embase
Available using RAVEN Login or Available
using NHS ATHENS
1. Select your database
Databases for literature searching

34. Your database will determine:
1. Your subject headings
2. Your operators (i.e., truncation
symbols)

35. Database Subject Headings
Medline MeSH
EMBASE EMTREE
CINAHL CINAHL Headings
Cochrane Library MeSH
Web of Science N/A
Scopus N/A

36. Which concepts are contained in the question: Does
ambulatory BP readings improve detection rates
for hypertension in patients with type 1 diabetes
mellitus?
1. Hypertension
2. Diabetes Mellitus, Type 1
3. Ambulatory blood pressure readings

37. Concept #1 Concept #2 Concept #3
Subject
Headings
Keywords
AND AND AND
OR
Hypertension Diabetes Mellitus, Type 1 Blood Pressure Monitoring, Ambulatory
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.

38. Operator 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.

39.  Concept(titles , objectives)
 Searching using criterias and parameters
 Screening
 Synthesizing the results

40.  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
Boolean operator or others

41. 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

43.  Two kinds: practical and methodological
1. practical screening criteria
 Is to identify a broad range of potentially
useful studies
2. methodological screening Criteria
 is to identify the best available studies

44. 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 and methods
 The clinical trials, studies

45. 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 analytical methods appropriate? (p value,
cooreation, regression, hypothesis etc)
 Are the results meaningful in practical & statistical
terms?*
*Fink, A. (2005). Conducting Research Literature Reviews. London: Sage.

46.  Apply practical screens
by using “limits” (may
also be called “search
options”)
 Eg. Advance option, by
date, by author ,time
published etc

48.  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 or else

49.  Export search results from each database or
website into a citation manager (i.e.,
RefWorks)
 Remove duplicates
 Remove inappropriate studies by applying
methodological screens

51.  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

52. 1. Describe current knowledge about your research
topic
2. Support the need for and significance of new
research
3. Explain research findings
4. Describe the quality of a body of research*
*Fink, A. (2005). Conducting Research Literature Reviews. London: Sage.

53.  Thanks