Presentation on theme: "Hilda Bastian SCR CONNECtions Webinar 17 July 2013 Systematic reviews and"— Presentation transcript:
Hilda Bastian SCR CONNECtions Webinar 17 July 2013 Systematic reviews and
Disclaimer This talk and these slides represent the work and opinions of the presenter, and do not constitute official positions of the National Center for Biotechnology Information (NCBI), the US National Library of Medicine (NLM), the National Institutes of Health (NIH) or the US Department of Health and Human Services (HHS).
xxxx Figure: Bastian et al (see following) In 1840,the entire collection could have been held by a four-shelf bookcase, shoulder high and 7 or 8 feet wide.
Why we need systematic reviews: There is a lot to know There are more than 75 trials a day & growing Bastian H, Glasziou P, Chalmers I. 75 trials & 11 systematic reviews a day: how will we ever keep up? PLoS Medicine (9):e
Conflicting information: the need for systematic reviews
Why we need systematic reviews : Research scatter Medical research is doubling every 7 years; the number of medical-related journals is doubling every 20 years* Trials on a topic could be published in hundreds of journals* – not all in the same database – and in registries Only sophisticated searching can reduce the risk of missing important evidence * Hoffmann T, Erueti C, Thorning S, Glasziou P. The scatter of research: cross sectional comparison of randomised trials and systematic reviews across specialties. BMJ 2012; 344:e3223.
Systematic reviewing: Search flowchart Searched: Embase, Medline, AMED, BIOSIS, CCMed, CDMS, CDSR, CENTRAL, CINAHL, DARE, HTA, NHS EED, Heclinet, SciSearch, several publishers’ databases, and reference lists of relevant secondary literature * Horvath K, Koch K, Jeitler K, Matyas E, Bender R, Bastian H, Lange S, Siebenhofer A. Effects of treatment in women with gestational diabetes mellitus: systematic review and meta-analysis. BMJ 2010; 340:c1395.
Why we need systematic reviews: Digesting data Cave: you often can’t combine data at all Can’t juggle the results of multiple studies in different groups of people in your head reliable Shortcuts are risky Usually not as simple as a head count: 3 positive + 1 negative positive
What we mean by “systematic review” Asks a structured, pre-specified question Pre-specified, systematic methods for: - finding all potentially eligible studies - selecting which studies will be included - assessing quality of included evidence - synthesizing and interpreting results Methods aim to minimize bias May or may not include quantitative synthesis (meta-analysis)
Systematic reviews, CER, evidence-based… PubMed Health concentrates on clinical effectiveness – but there are systematic reviews that answer other questions CER can be “comparative effectiveness research” or “clinical effectiveness research”: may or may not be systematic reviews Systematic reviews of systematic reviews: might be called overviews – might have both primary & secondary studies “Rapid reviews”, “mini-reviews”, “evidence-based” Guidelines, health technology assessments (HTA) and systematic reviews are not the same thing – except for the cases where they are!
“Knowledge translation” Efforts aiming to make the results of systematic reviews accessible – to consumers, clinicians, policymakers Critical appraisal: efforts aiming to sift out the most reliable systematic reviews From AHRQ Effective Health Care Program:
PubMed Health Aims to: Help people find systematic reviews Understand what they find How: Gathering systematic reviews, knowledge translation & educational materials Background articles – NLM Technical Bulletin:
Finding (good) systematic reviews Found & critically appraised in DARE (Database of Reviews of Effects) Cochrane Database of Systematic Reviews (Cochrane Library) Unselected: INAHTA database (with DARE) PubMed Health * All 3 PubMed Health
Aim: a comprehensive clinical effectiveness review search Cochrane reviews + DARE* reviews + systematic reviews by health technology assessment agencies Now around 26,000 systematic reviews from the last 10 years Simultaneous search of PubMed with “Clinical Queries” systematic review filter * Database of Reviews of Effects
Helping people understand Knowledge translation materials & medical encyclopedia Section on “Understand Clinical Effectiveness” – includes educational articles & full text books “Behind the Headlines”: critical appraisal of studies reported in the news Tweets / Google+ / Facebook on clinical effectiveness concepts
PubMed Health partners include: NHS Centre for Reviews & Dissemination (producers of DARE) Cochrane Collaboration Health technology assessment agencies, including AHRQ (Agency for Healthcare Research & Quality) Producers of knowledge translation materials, including National Cancer Institute (NCI)