4. Literature review
“take a simmering topic, extract the juice of an argument,
add the essence of one filing cabinet, sprinkle liberally with
your own publications and sift out the work of noted
detractors or adversaries”
https://www.flickr.com/photos/litlnemo/3181163906
https://www.flickr.com/photos/rachelandrew/178930904
5. From research question to search question
Systematic search
Screening
inclusion/exclusion criteria
Critical appraisal
validity/relevance
Data synthesis
The systematic review process
6. From research question to search
question
PICO(S)
Population
Intervention (or exposure)
Comparison
Outcome
Study
7. From research question to search
question
SPICE
Setting – Where? In what context?
Perspective – For who?
Phenomenon of Interest – What?
Comparison – what else?
Evaluation – How well? What result?
8. Development of children from mothers with
epilepsy (anti-epileptics during pregnancy)
Population
Intervention/Exposure
Comparison
Outcome
Study
https://www.flickr.com/photos/erin_ryan/2718885808
9. What is the effect of taking antiepileptics
while pregnant on child development?
Population: Pregnant women with epilepsy
Intervention: anti-epileptics
Comparison: none
Outcome: child development
Study: cohort studies and observational
research
12. Does it matter?
Pregnancy outcomes
AND
Anti-epileptics
3.636 results 6.709 results
Pregnancy
AND
Epilepsy
AND
Development
13. Protocols
Centre for Reviews and Dissemination
Guidance: Systematic Reviews: CRD's guidance for
undertaking systematic reviews in health care
Campbell Collaboration
The production of a systematic review
PROSPERO database
14. Guidelines
PRISMA statement
Preferred Reporting Items for Systematic Reviews and
Meta-Analyses
Equator network
Reporting guidelines
E.g. ENTREQ for synthesis of qualitative research
See www.equator-network.org/
16. General - specific
ethnic minority or Asian
physiological measures or cortisol
Synonyms and related terms
social phobia or social anxiety or blushing
Acronyms
Major Depressive Disorder or MDD
Search terms
17. Spelling
US – UK: behavior or behaviour
Single - plural: child or children
Verb tenses: cry, crying or cried etc
Opposites
fertility or infertility
Historical language
Changes in DSM
Countries
Search terms
18. Abstract There is ample evidence for the existence of an association between
sleeplessness and worry. Not much is known, however, concerning the nature
of this relationship. Therefore, a study was conducted investigating the causal
relationship between sleeplessness and nocturnal worry. A 2 x 2 (Worry x
Induced sleeplessness) analysis of covariance design was used. The first factor
consisted of a subject variable defined by scoring either high or low on a trait
measure of worry (the Penn State Worry Questionnaire) and the second factor
consisted of 300 mg caffeine or placebo. A total of 96 female undergraduate
students participated. The dependent variables comprised measures of
nocturnal worry (the Night-Time Thoughts Questionnaire) and subjective and
objective sleep parameters. Overall, caffeine caused an increase in nocturnal
worry and sleeplessness. A significant interaction effect occurred between
Worry and Induced sleeplessness on one of the objective sleep parameters, but
no other interaction effects were significant. The results suggest that worry may
occur as an epiphenomenon of sleeplessness.
Subject
Headings
*Anxiety
*Caffeine
*Cognitions
*Insomnia
Database: PsycINFO
Night-time thoughts in high and low worriers:
Reaction to caffeine-induced sleeplessness
30. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
parent*
OR
child*
OR
family
694.000 titles
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
31. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
role reversal
OR
role conflict
694.000 titles
parent*
OR
child*
OR
family
3.200 titles
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
32. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
immigra*
OR
ethnic
82.000 titles
role reversal
OR
role conflict
parent*
OR
child*
OR
family
694.000 titles 3.200 titles
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
33. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
immigra*
OR
ethnic
role reversal
OR
role conflict
parent*
OR
child*
OR
family
ANDAND ANDAND
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
34. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
parent*
OR
child*
OR
family
role reversal
OR
role conflict
immigra*
OR
ethnic
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
35. You searched a database and found far too
few results. How can you broaden your
search and increase the search results?
Choose the three right answers from the
following.
A. Add search terms and combine with AND.
B. Search more fields, for example "words in
abstract".
C. Limit to the most recent publications.
D. Combine the search terms with OR.
E. Use different search terms, for example
synonyms.
immigra*
OR
ethnic
parents
OR
child
OR
family
role reversal
OR
role conflict
36 titles
694.000 titles 3.200 titles 82.000 titles
De rolwisseling tussen ouders en kinderen in
allochtone gezinnen
38. Other Databases
Health care
Embase, PsycINFO, CINAHL
Sportdiscus, Pilots, LILACS
Cochrane Library
Sociology
Sociological Abstracts, IBSS, SocIndex, Campbell Library
Other
ERIC, Linguistic and Language Behavior Abstracts (LLBA)
Web of Science, Google Scholar
39. Google Scholar search query
Maximum of 1000 search results
Screen first 200-500 results and report date and search
query
Maximum of 200 characters per query
OR can be replaced by vertical line (above Enter on your
keyboard)
AND is the default combination; use " " for phrases
Less need for word variations
parents | children | family "role reversal" | "role
40. Other complementary search
strategies
Citation tracking
Web of Science and Google Scholar (cited by..)
Systematic reviews and meta-analyses
Authors
Hand searching
Journals
Conference proceedings
Consulting experts
41. Challenges
Books
Worldcat, Picarta, Google Books
Grey literature
What: reports, conference proceedings, dissertations
Where: websites, repositories..
E.g. Afrika Studies Centre Leiden
Other languages
https://en.wikipedia.org/wiki/Batgirl#mediaviewer/File:Batgirls.jpg
43. Publication Bias
Statistics
Unpublished research
Contacting authors
Clinicaltrials.gov
International Clinical Trials Registry Platform (ICTRP) from
the World Health Organization (WHO)
Grey literature
Dissertations
Conference Proceedings
https://www.flickr.com/photos/rdennis/11948643
47. Further reading - General
Booth, A., Papaioannou, D., & Sutton, A. (2011).
Systematic approaches to a successful literature
review. SAGE Publications Limited.
Gough, D., Oliver, S., & Thomas, J. (2012). An
introduction to systematic reviews. Sage
Publications
Systematic searching for reviews (online tutorial,
VU university)
48. Further reading – Qualitative research
Hannes, K., & Lockwood, C. (2011). Synthesizing qualitative research:
Choosing the right approach. John Wiley & Sons.
Michael Saini, Aron Shlonsky (2012) Systematic Synthesis of Qualitative
Research. Oxford University Press. 978-0195387216
Harris Cooper (2010) Research Synthesis and Meta-Analysis. A Step-by-
Step Approach Fourth Edition. Sage
Pope, C., Mays, N. & Popay, J. (2007). Synthesizing qualitative and
quantitative health evidence. A guide to methods. Open University Press
Dixon-Woods M, Agarwal S, Young B, Jones D, Sutton A. (2004) Integrative
approaches to qualitative and quantitative evidence. London: Health
Development Agency
49. More..
Filters for qualitative research – ISSG Search
Filters Resource
Goodyear-Smith, F. A., van Driel, M. L., Arroll, B., &
Del Mar, C. (2012). Analysis of decisions made in
meta-analyses of depression screening and the risk
of confirmation bias: A case study. BMC medical
research methodology, 12(1), 76
http://www.biomedcentral.com/1471-2288/12/76
Notas del editor
EBM-(evidence based) guidelines.
Synopses & Syntheses*: a synopsis is a summary and critical appraisal of one article, whereas synthesis is a summary and critical appraisal of a topic (which may answer several questions and may cover many articles).
Systematic Reviews (a systematic summary and critical appraisal of original studies) which may or may not include a meta-analysis.
Original Studies.
Purposes for a review
To place work(s) in the context of how it contributes to an understanding of the subject under review
To identify new ways to interpret previous research
To resolve conflicts across seemingly controdictory studies
Avoid reinventing the wheel, or worse, the flat tire
Source: Booth, A., Papaioannou, D., & Sutton, A. (2011). Systematic approaches to a successful literature review. Sage.
P Patient/Population - What people or patient group do I want information on?
I Intervention – What is the intervention (treatment, cause, prognostic factor) of interest?
C Comparison – What is the main alternative to compare with the intervention (if necessary)?
O Outcomes - What do I hope to accomplish? What could this exposure affect?
Search query Pubmed:
"sleep initiation and maintenance disorders"[MeSH] NOT (sleeplessness[tiab] OR sleep disorder[tiab])
Search query Medline (OvidSP):
"sleep initiation and maintenance disorders“/ NOT (sleeplessness.ti,ab. OR sleep disorder.ti,ab.)
Problematic aspects of Pubmed
- Limited amount of truncation (*) possibilities (only 600 word variations)
- Quotation marks with asterix doesn’t work (compare "word combination*" with word combination* and word and combination* )
- Some word combinations won’t work because Pubmed does phrase indexing instead of word indexing (e.g. "right not to know"[tiab] )
Grey literature is informally published written material (such as reports) that may be difficult to trace via conventional channels such as published journals and monographs because it is not published commercially or is not widely accessible