Evidence Pyramid – Publication Types
Evidence-Based Guidelines
Systematic Review & Meta-
analysis
Randomized Controlled Trials
Cohort Studies
Case Control Studies
Case Series, Case Reports
S y n t he s e s
St
ud
ie
sHigher Quality of Information
Lower Quality of Information
Fewer Articles
More Articles
Agenda
• Distinguish a systematic review from a standard literature review• Locate the following in PubMed• Reviews• Systematic Reviews• Meta-Analyses
• Introduce Cochrane Database of Systematic Reviews
Source: Evidence-Based Living Blog (Cornell University) http://evidencebasedliving.human.cornell.edu/
Definition
Literature ReviewQualitatively summarizes evidence on a topic using informal or subjective methods to collect and interpret studies.
Systematic ReviewHigh-level overview of primary research that identifies, selects, synthesizes, and appraises all relevant high quality research evidence
Goal
Literature Review• Provide summary or
overview of topic
Systematic Review• Answer a focused clinical
question• Eliminate bias
Question
Literature Review• Can be a general topic or a
specific question
Systematic Review• Clearly defined and
answerable clinical question• Recommend using PICO as a
guide
Components
Literature Review• Pre-specified eligibility
criteria• Systematic search strategy• Assessment of the validity of
findings• Interpretation and
presentation of results• Reference list
Systematic Review• Introduction•Methods• Discussion• Conclusion• Reference list
Hormone therapy for preventing cardiovascular disease in post-menopausal womenMain Cm Knight B, Moxham T, Sanchez RG, Sanchez Gomex LM, Figuls MR, Cosp XB.
Hormone therapy for preventing cardiovascular disease in post-menopausal womenMain Cm Knight B, Moxham T, Sanchez RG, Sanchez Gomex LM, Figuls MR, Cosp XB.
Authors
Literature Review
• 1 or more
Systematic Review
• 3 or more
• Understanding of topic• Perform searches in one or
more database
• Thorough knowledge of topic• Perform searches in all relevant
database• Statistical analysis resources
(meta-analysis)
Literature Review Systematic Review
Skills
Time
Literature Review•Weeks to months
Systematic Review•Months to years• Average eighteen months
Value
Literature Review• Provides summary of the
literature on a topic
Systematic Review• Connects practicing
clinicians to high quality evidence• Supports evidence-based
practice
All Review Articles
Systematic Reviews
Meta-Analyses
Adapted from: Pai M, McCulloch M, Gorman JD, Pai N, Enanoria W, Kennedy G, Tharyan P, and Colford JM. “Systematic reviews and meta-analyses: An illustrated, step-by-step guide”The National Medical Journal of India (2004)
Finding review articles:Use “Article Type” filter
Finding systematic reviews:Use Basic Search
Agenda
• Distinguish a systematic review from a standard literature review• Locate the following in PubMed• Reviews• Systematic Reviews• Meta-Analyses
• Introduce Cochrane Database of Systematic Reviews