Evidence Pyramid
Systematic Reviews and Meta-Analysis are widely considered the gold-standard approach to summarizing and synthesizing evidence. The authors who developed the graphic below suggest that these may be viewed as tools for consuming evidence. Study design on its own is not enough to evaluate for evidence quality. Study methodology needs to be assessed for limitations and quality of evidence through critical appraisal. Evidence quality may then inform the use of a grading system such as the one developed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group which rates evidence quality when making guideline recommendations.
Murad MH, Asi N, Alsawas M, Alahdab F. New evidence pyramid. Evid Based Med. 2016;21(4):125-127. doi:10.1136/ebmed-2016-110401
Meta Search Engines
- SUMSearch2 This link opens in a new windowSUMSearch selects the best resources for your question, formats the question for each resource and makes additional searches based on the results.
- TRIP Database This link opens in a new windowThis clinical search engine allows users to quickly find high-quality research evidence to support practice or care. It also searches for images, videos, and patient education handouts.
Other Sources of Evidence
- BestBETs This link opens in a new windowBrief and structured evidence appraisal and summaries specific to emergency medicine.
- Stat!Ref Evidence Alerts1. Click on the "My Stat!Ref" link in top right corner.
2. Type your e-mail address in the appropriate box. Login or register for an account.
3. Select Alerts tab
4. Click STAT!Ref Evidence Alerts link
5. Click on the Medicine, Nursing or Rehab tab. Select your discipline, categories and populations.
6. Click the Apply Alerts button.
Summaries: Clinical Information Tools
Summaries of topics and guidelines.
- National Institute for Health and Clinical Excellence (NICE) This link opens in a new windowGuidelines for United Kingdom (UK) National Health Services (NHS).
- UpToDate This link opens in a new window
Syntheses: Systematic Reviews
Syntheses resources include the publication types systematic review and meta-analysis.
- MEDLINE (Ovid) This link opens in a new windowLimit search to publication types: Systematic Review, Meta-Analysis, and/or Guidelines
- PubMed@USC This link opens in a new windowLimit search to publication types: Systematic Review, Meta-Analysis, and/or Guidelines.
Synopses: Article Appraisals
Critically-appraised journal articles.
Studies: Primary Research Articles
- PubMed@USC This link opens in a new windowLimit search to publication types: Randomized Controlled Trials, Cohort Studies, Case-Control Trials, etc.
- PubMed Clinical QueriesChoose Category (question type) and Scope to obtain relevant study types.
Studies: Unpublished Trials
- ClinicalTrials.gov This link opens in a new windowRegistry and results database; includes information about publicly & privately funded studies including; completed & ongoing trials, research design, results, and contact information.
Appraise the Evidence
Now that you have searched for evidence, continue on Step 3: Appraising the Evidence.