WISER: Sciences. Doing a Systematic Review

1. WISER: Sciences. Doing a Systematic Review Jo Hunter & Linda Atkinson

2. Workshopsin Information Skillsand Electronic Resources What is a Systematic Review? “A scientific tool which can be used to summarise, appraise and communicate the results and implications of otherwise unmanageable quantities of research” (NHS CRD, 1996)

3. Workshopsin Information Skillsand Electronic Resources What is a Systematic Review? • Systematic in identifying/evaluating • Objective in interpretation • Explicit in statement of objectives • Reproducible in methodology (Greenhalgh, 2000)

4. Workshopsin Information Skillsand Electronic Resources What about “Meta-analysis”? “A specific statistical technique used to combine the results of several studies into a single estimate” (Sackett et al., 1991)

5. Workshopsin Information Skillsand Electronic Resources Systematic Review - Advantages • Summarise information • Overcome biasinherent in small studies • Overcome lack of generalisability • Heterogeneity (inconsistency in results) can be identified

6. Workshopsin Information Skillsand Electronic Resources Which organisations produce systematic reviews? • Cochrane Collaboration • NHS Centre for Reviews and Dissemination • Campbell Collaboration

7. Workshopsin Information Skillsand Electronic Resources The Cochrane Collaboration • Formed in 1993 • International, with several Centres • Systematic reviews available via the Cochrane Library www.nelh.nhs.uk/cochrane.asp

8. Workshopsin Information Skillsand Electronic Resources The NHS CRD • Formed in 1994 • Works with the UK Cochrane Centre • Produces guidance on writing systematic reviews • Provides access to systematic reviews www.york.ac.uk/inst/crd/index.htm

9. Workshopsin Information Skillsand Electronic Resources The Campbell Collaboration • Set up along similar lines to the Cochrane Collaboration • Access to systematic reviews re: social and educational policies/practices www.campbellcollaboration.org

10. Workshopsin Information Skillsand Electronic Resources What’s the best methodology? • Updated guidance from the NHS CRD www.york.ac.uk/inst/crd/report4.htm • Up-to-date advice from the NHS CRD www.york.ac.uk/inst/crd/reviews.htm • The Cochrane Handbook www.cochrane.org/resources/handbook

11. Workshopsin Information Skillsand Electronic Resources Three Broad Stages • Planning – identify need, prepare proposal, develop protocol • Conducting – find, select, appraise, extract, synthesise literature • Reporting – write up and disseminate results

12. Workshopsin Information Skillsand Electronic Resources Stage 1: Planning • Is there a need? • Find a team • Someone to obtain funding • Someone to do most of the work • An information specialist • A methodologist • A content expert • An advisory group

13. Workshopsin Information Skillsand Electronic Resources Stage 1: Planning • Draw up a protocol • Background & rationale • Study question(s) • Inclusion criteria • Details of literature search • Data extraction • Proposed analysis • Plans for reporting/dissemination (Dinnes, 2000)

14. Workshopsin Information Skillsand Electronic Resources Stage 2: Conducting the review • Literature search - comprehensive • Select studies – use an eligibility form • Assess qualityof selected studies – use checklist • Data extraction – use forms/tables • Data synthesis – qualitative & quantitative

15. Workshopsin Information Skillsand Electronic Resources Literature search • Focus on reports from RCTs • Comprehensive – minimise selection bias • Electronic Databases – 100s exist • Search strategy – customise for each database • Handsearching – not all RCT reports are included in databases, or difficult to find

16. Workshopsin Information Skillsand Electronic Resources Search Strategy • Comprehensiveness vs. precision • Iterative process • 3 sets of terms: • the health condition of interest • the intervention evaluated • types of study design included (usually RCTs)

17. Workshopsin Information Skillsand Electronic Resources Stage 3: Reporting & Dissemination • Succinct and consistent report • Publish in a professional journal • Promote in conference presentations www.nelh.nhs.uk/cochrane.asp

18. Workshopsin Information Skillsand Electronic Resources SUMMING UP Systematic Reviews: • Are time consuming • Need Planning • Must be documented at all stages • Need rigorously applied inclusion criteria • Need standardised critical appraisal method • Need statistical expertise • Should include your methodology

19. Workshopsin Information Skillsand Electronic Resources TOP TIPS • Make sure you learn how to use a reference management system such as Endnote/Reference Manager/Procite 2. Seek out your Local Subject Librarian for advice on resources and searching strategies

20. Workshopsin Information Skillsand Electronic Resources Bibliography • Dinnes J. (2000). Protocols for systematic reviews. Presentation at the Systematic Review Development Programme, Centre for Statistics in Medicine, Institute of Health Sciences, Oxford 11/09/00. • Greenhalgh T. (2000). How to read a paper: the basics of evidence based medicine. (2nd edition). London: BMJ Publishing. • Sackett D., Haynes RB., Guyatt GH. & Tugwell P. (1991). Clinical Epidemiology: A basic science for clinical medicine. 2nd edition. Little, Brown & Company.

21. WISER: Sciences. Doing a systematic review What did you think of this presentation? www.oucs.ox.ac.uk/courses/feedback Jo Hunter & Linda Atkinson Oxford University Health Care Libraries