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UCQ

Evidence-based Practice (EBP)

Answer basic questions to improve your practice.

Levels of Evidence

he 6S Hierarchy of Evidence is a model that categorizes evidence to help guide clinicians in finding the highest quality research available to use in clinical decision making. 

How does the 6S Hierarchy work?

  • The highest quality evidence is found at the top of the pyramid. It is recommended that searching for evidence begin at the top (or the highest possible level) of the pyramid. 
  • Each level of the pyramid draws on research evidence from the lower levels. 
    • Secondary pre-appraised evidence refers to research studies that have been critically appraised by experts and includes only research of higher quality, and that are regularly updated so that the evidence is current (DiCenso, A., Bayley, L., & Haynes, B., 2009). Work down the pyramid through the different levels of secondary pre-appraised research. 
      • Literature Reviews are secondary pre-appriased evidence.
    • Primary original research or individual studies make up the majority of research evidence available. Evidence at this level is pre-appraised and should be the last stop in the search for evidence.

DiCenso, A., Bayley, L., & Haynes, B. (2009). Accessing pre-appraised evidence: fine tuning the 5S model into a 6S model. Evidence-based nursing, 12(4), 99-1

6S Defined

Characteristics of Evidence

 
Level of Evidence Definition Characteristics (How can you know?)
Summary (Clinical Practice Guidelines or Evidence Based Care Sheet)
  • Summarizes the highest level of evidence available, integrating evidence based information and clinical problems in the form of clinical practice guidelines, best practice guidelines and information in text books.
  • Shorter in length, 2-5 pages average
  • References will be numerous or will include synthesis of high levels of evidence
  • They will not be as prevalent, not available on all topics
Synopsis of Syntheses
  • Summary & analysis of Systematic Review of Meta-Analysis
  • Summary and analysis of the methodology and results of a single research study that was conducted
  • Shorter in length (1 page, average)
  • List of references will be short as it is evaluating one 1 research study
Syntheses (Systematic review or Meta-analysis)
  • Research study design that draws conclusions by analyzing all the single studies conducted on a topic 
  • Most common are: Systematic Reviews and Meta-Analysis (like SR but uses statistics to draw conclusions from research).
  • Longer in length (10-15 pages, average)
  • Includes many references
  • Methodology will discuss the search strategy used - which databases, what keywords, limiters... 
  • Study of many studies on a topic
Synopsis of a Single Study
  • Summary & evaluation of a research study that has been done
  • Summary and analysis of the methodology and results of a single research study that was conducted
  • Not primary research 
  • Shorter in length (1 page, average)
  • List of references will be short as it is evaluating one 1 research study
Single Studies Primary research study which was conducted on focus topic
  • Longer in length (10-15 pages, average)
  • Include many references
  • Methodology will discuss participants, how participants were studied, type of measurement used to study participants (survey, interview, physical exam, tests, etc...) and also outline ethics approval. 
  • Most common type of research found because it doesn't take as much time to produce as higher levels of evidence