Introduction to Systematic Review(and some really cool research tips)
10:00-11:30Interim Research Report
Lecture 0J13Dr Viv Rolfe
vivrolfe.com
Outline
• What are systematic reviews?• Why are they different from narrative
reviews? What are your review processes?• Whizz through Cochrane, Evidence Based
Medicine, the main steps and publication.• Focus on 3 main steps important for ANY
researcher.• Discussion about the coursework.
• What is a systematic review?• Is it different from a normal literature review
or the introduction to your thesis?
A systematic collates all available evidence that fits pre-specified eligibility criteria in order to answer a specific research question” (Cochrane 2015) Extensive searches, selection of most precise papers
and pooling of data. Top of the ‘evidence hierarchy’.
A Systematic Review of the Socio-Ethical Aspects of Massive Online Open CoursesVivien Rolfe (2015) EDUCATION INTERVENTION MOOC / QUALITATIVE
Probiotics for maintenance of remission in Crohn's disease. Rolfe VE (2006) INTERVENTION
BOB CAT: a Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia. Bennett C et al (2015)INTERVENTION / DIAGNOSTIC / PROGNOSIS
Rapid diagnostic tests for uncomplicated P. falciparum malaria in endemic countries. Katharine Abba et al (2011) DIAGNOSTIC TEST
The effect of tuberculosis treatments on incidence and mortality of active pulmonary tuberculosis in children co infected with HIV. Theda, MSc student (2015) INTERVENTION
Cochrane
• http://www.cochranelibrary.com
• Cochrane 2015. http://www.cochrane-handbook.org
The Process
• How do you normally go about a literature search?
1. How to write a killer research question
• Write down your research question if you have one or make one up.
1.1 PICO(S)• P = population or patient group• I = intervention = what intervention /
inventive step am I looking at?• C = what is the alternative to compare to, or
the control?• O = what are the outcome measures, or things
I’m actually going to measure?• (S) you can search for study type
Aslam S & Emmanuel P (2010). “PICO method”
Probiotics for maintenance of remission in Crohn's disease
• In adults with Crohn’s disease (P) are probiotics (I) effective for maintaining remission (O) compared to controls (C)? (RESEARCH QUESTION)
• In adults with Crohn’s disease (P) do probiotics (I) improve symptoms? (O)
• Are probiotics (I) effective for maintaining remission (O) in Adults with Crohn’s disease? (P)(PUBLISHING QUESTION, PUNCHY, INTERESTING)
2. Writing a search strategy
• Write down your research question if you have one or make one up.
2.1 Where to search?
• Online, offline (hand searching), contacting experts and authors. Global. No limits.
• Research suggests you can get 80% there with online databases.
• Databases to find journal articles:– E.g. Medline (PubMed), Scopus, Science Direct, Biomed Central,
CINAHL, Academic Search Premier• Databases focusing on evidence based practice:– Cochrane Library (Systematic Reviews)– TRIP (http://www.tripdatabase.com)– Bandolier (http://www.medicine.ox.ac.uk/bandolier/)
2.2 Keyword research
Adults with CD
Probiotics Remission Controls Study type (e.g. RCT)
HOW?
Medical Subject Headings (MeSH)
Search for keywords in TITLE, ABSTRACT, KEYWORDS or ALL FIELDS
2.3 Boolean notation
Clinical trialORRCT
ProbioticsOR
LactobacillusOR
Bifidobacter
Crohn colitisOR
Crohn diseaseORIBD
Clinical trialORRCT
ProbioticsOR
LactobacillusOR
Bifidobacter
Crohn colitisOR
Crohn diseaseORIBD
AND
CHECKOUT THE PUBMED TUTORIALShttp://www.nlm.nih.gov/bsd/disted/pubmedtutorial/020_460.html
“PHRASES GO IN QUOTES”* Truncates words# Letter wildcard[….] directs the search e.g. TITLE [ti] MeSH [MH] PUBLICATION TYPE [pt]
A BIT OF PLAYING AROUND WILL GET IT RIGHT.THIS IS ONLY FOR MEDLINE (PUBMED)
http://vivrolfe.com/blog/methods-for-conducting-effective-desk-top-research/
http://vivrolfe.com/learning-teaching/study-skills/seek-and-ye-shall-find/
MeSH versus Keyword Searching
• Introduction to MeSHhttp://www.nlm.nih.gov/mesh/introduction.html
• See video
• Decide the pragmatic approach for your research. Cochrane review or good research dissertation?
Pragmatic
• Introduction to MeSHhttp://www.nlm.nih.gov/mesh/introduction.html
• See video
3. Selecting your evidence
• How do you chose what papers to include in your research?
3.1 Setting inclusion and exclusion criteria
• Are probiotics (I) effective for maintaining remission (O) in Adults with Crohn’s disease? (P)(PUBLISHING QUESTION, PUNCHY, INTERESTING)
• Inclusion – (I)probiotics in all forms, as supplements, in foodstuffs etc….(P) all adults, with existing Crohn’s or in remission
• Exclusion – any co-morbidities? Would state here any limits due to date or language (if you really must).
3.2 Critical appraisal
• Read Trish Greenhalgh’s work on ‘how to trash papers’.
3.3 Use Cochrane toolkits
• Slightly more in depth than normal appraisal• A rigorous assessment of ‘risk of bias’
(INTERVENTION)• Assessment of quality with QUADAS tool
(DIAGNOSTIC STUDY)
Bias?• The risk of bias occurs at each point of human intervention
or as part of the study design. It is a systematic error that can be small or large, have a negative or positive effect on the results.
• An a review that uses meta-analysis for pooling the data, HETEREGENITY (a %) expresses the variation of results due to bias. This gives you something to discuss.
• Therefore writing up – you would be more tentative with conclusions from a heterogenous bunch of studies than you would a closer packed group with less risk of bias.
Cochrane Handbook 2015
Whiting et al 2011
Selection biasAttrition bias
Performance biasDetection bias
Some examples from practice?
Diagnostic testing(e.g. search strategies, data extraction and quality assessments)
• http://onlinelibrary.wiley.com/enhanced/doi/10.1002/14651858.CD011592/
• http://onlinelibrary.wiley.com/enhanced/doi/10.1002/14651858.CD011634/ (data extraction example)
• http://onlinelibrary.wiley.com/enhanced/doi/10.1002/14651858.CD010402/#CD010402-sec1-0005 (search strats)
References
• Aslam S & Emmanuel P (2010).Formulating a researchable question: A critical step for facilitating good clinical research. Indian J Sex Transm Dis. 2010 Jan-Jun; 31(1): 47–50 PICO
• Whiting PF, Rutjes AW, Westwood ME, Mallett S, Deeks JJ, Reitsma JB, et al. QUADAS-2: A Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. Ann Intern Med. QUADAS
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