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An evidence-based approach to research support: applying systematic review methods. Morgan & Mann


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Presented at LILAC 2009

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An evidence-based approach to research support: applying systematic review methods. Morgan & Mann

  1. 1. An evidence-based approach to research support Fiona Morgan and Mala Mann LILAC 1 April 2009
  2. 2. Identifying the Evidence Base • Background and history • Outline of systematic review methods • Identifying the needs of the researcher • Developing a systematic search strategy
  3. 3. Evidence-based Medicine • Archie Cochrane – British medical researcher – Contribution to development of epidemiology as a science • Cochrane Collaboration (1993) – Improving healthcare decision- making globally, through systematic reviews of the effects of healthcare interventions
  4. 4. Cochrane systematic reviews • Evidence-based medicine – Clinical answers for more effective healthcare – Pinnacle of the evidence pyramid • Critical summaries of the evidence – Randomised controlled clinical trials • Clear methodology – Transparent – Reproducible
  5. 5. Expansion of evidence-based methods • 1999 UK Government White Paper Modernising Government: “Government must…produce policies that really deal with problems; that are… shaped by the evidence rather than a response to short-term pressures…. “This Government expects…better use of evidence and research in policy making.”
  6. 6. What does the researcher want? • A systematic literature search? – Finding all the information on a topic area • Literature review • Informs research • A systematic review of the literature? – Finding and using the best available evidence to answer a specific question
  7. 7. A systematic review of the literature • Explicit, reproducible methodology – Usually conducted by a team – Systematic literature search – Study selection using pre-defined inclusion and exclusion criteria – Critical appraisal of included papers – Data extraction – Statistical or narrative summary – Highlights strengths and weaknesses
  8. 8. Systematic review or systematic literature search? • Same search principles apply • Methodology adapts effectively • Aim is to find ALL the relevant evidence • The finished product only as good as the information that underpins it.
  9. 9. What is a search strategy? A search strategy is a plan that helps you look for the information you need. [PubMed]
  10. 10. Developing a systematic search strategy 1. Define the question and break it down 2. Set limits 3. Search each concept and combine 4. Test and refine the search 5. Select databases and other sources of information
  11. 11. PICO/PECO P = Population/problem I/E = Intervention/Exposure C = Comparison/Control O = Outcome
  12. 12. Population/ Problem Intervention/ Exposure Comparison/ Control Outcome Inner city residential area Intervention: Neighbourhood Watch scheme Exposure Living in social housing Similar area no watch scheme Being an owner -occupier Reduction in crime Crime rate
  13. 13. Question PICO • In an inner-city residential area, does the introduction of a neighbourhood watch scheme reduce the level of crime when compared with no watch scheme? PECO • In an inner-city residential area, does the population living in social housing experience a higher level of crime when compared with those living in owner occupied accommodation?
  14. 14. Question must be…. • Clear • Answerable • Focused Counsell C (1997). Annals of Internal Medicine, 127: 380-387 “Ask a poor question and you will get a poor review”
  15. 15. Set Limits • Consider inclusion/exclusion criteria – Age group – Publication date – Language – Study design – Settings
  16. 16. List all relevant keywords Remember…. • Synonyms and acronyms • American and British spellings • Hyphenated vs non-hyphenated
  17. 17. Identify relevant subject headings • Match keywords to headings • Check how key papers and references are indexed • Subject headings – – To explode or not to explode?
  18. 18. Wildcards & Truncation * $(n) ? # Manag* home$1 Colo?r Wom#n Manage Manages Manager Managers Managing Management Home Homes (not homeless or homelessness) colour color woman women
  19. 19. Combining Search Terms • Using Boolean Logic –AND narrows the search • Papers containing both concepts together will be retrieved –OR broadens the search • Articles containing either concept are retrieved • NOT removes a concept • Cuts a concept out of a search
  20. 20. ADJn Retrieves records containing terms in any order within a specified number (n) of words of each other eg asthma ADJ inhaler The words must appear next to one another “an asthma inhaler” Eg asthma ADJ3 inhaler The words must be within 3 of each other (in any order): “an inhaler for asthma” “using an inhaler for moderate asthma”
  21. 21. Search strategy 1. child or Child Abuse/ 2. child 3. (battered child or shaken baby or battered baby).mp. 4. 1 or 2 or 3 5. (child* or infant* or baby).mp. 6. non-accidental injur*.mp. 7. non-accidental 8. (non-accidental* and injur*).mp. 9. soft tissue injur*.mp. 10. physical 11. (or/6-10) and 5 12. 4 or 11 13. fractur*.mp. 14. 12 and 13 15. (investigat* adj3 fract*).mp. 16. (radiolog* adj3 fractur*).mp. 17. (roentgen* adj3 fract*).mp. 18. skeletal 19. bone scan*.mp. 20. Isotope Bone Scan*.mp. 21. 22. 23. Tomography, X-Ray Computed/ 24. ((paediatric or pediatric) adj3 radiolog*).mp. 25. ((paediatric or pediatric) adj3 nuclear medicine).mp. 26. or/15-25 27. (ageing adj3 fractur*).mp. 28. ((dating or date) adj3 fractur*).mp. 29. (pattern* adj3 fractur*).mp. 30. 31. or/27-30 32. 26 or 31 Kemp et al. BMJ 2008;337:a1518
  22. 22. Searching for study designs Search Filters Collections of search terms designed to retrieve selections of records InterTASC Information Specialists' Sub-Group http:// McMaster University
  23. 23. Balance between sensitivity and specificity Sensitivity • Proportion of relevant articles identified by a search strategy, expressed as % of all relevant articles on a given topic • The ability to identify all relevant articles on a given topic Specificity • Proportion of relevant articles identified by the search, as a % of all articles (relevant and irrelevant) • The ability of a search to exclude irrelevant articles Centre for Reviews and Dissemination, CRD Report 4 (2009)
  24. 24. Is the strategy adequate? • Depends on the size of the evidence base for the topic. • Rough guide - 1:10 or 1:20 relevant references • Use key papers to test the search strategy – Does the search pick up all key papers? – If key papers have been missed why? – Does search need adjusting?
  25. 25. Range of general, specialist and grey literature databases General ASSIA, CINAHL, Cochrane Library Embase, Medline, Science Citation Index, SCOPUS Social Care Online, Sociological Abstracts, Social Sciences Citation Index Specialist Age Line, ChildData, Community Wise, ERIC, IBSS, IDOX PsycINFO Grey Literature HMIC, Open SIGLE, ReGARD, conference abstracts, websites
  26. 26. Snowballing • Identify grey literature and new or missed studies • Grey literature – Conference proceedings – Trial registers – Internet searching • Google scholar • Web sites of relevant organisations • Contacting experts – Experts in the field and research networks • Reference lists of relevant papers
  27. 27. Record everything • Systematic review methodology should be transparent and replicable • Record sources searched, search strategies and results • Use reference management software to manage the search results
  28. 28. And finally…A few tips • Check out the literature • Are there other reviews in the topic area? • What sources of information do they use – databases, grey literature? • How are key papers indexed in the databases? • Use and adapt other people’s search strategies - it’s not plagiarism.
  29. 29. Thank you