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Evidence based practice

Overview of evidenced based practice

Secondary or pre-appraised sources

The strongest evidence is in the secondary or pre-appraised research.

The 6S model evidence pyramid

DiCenso A, Bayley L, Haynes B. Accessing preappraised evidence: fine-tuning the 5S model into a 6S model, ACP J Club. 2009; Vol 151 Issue 3: p1

The pyramid is divided into levels with the strongest evidence at the top - start at the top and drill down

Begin with ‘Summaries’ as ‘Systems’ is not  widely used.  If you cannot find the information in ‘Summaries’ continue down the pyramid remembering that the strength of the evidence decreases as you go further down the pyramid.


Evidence-based guidelines – highest level in Summaries

Synopses of Syntheses

  • ACP Journal Club (Evidence-Based Medicine Reviews (EBMR, Ovid menu)
  • Database of Abstracts of Reviews of Effectiveness (DARE) (EBMR, Ovid menu)

Syntheses (Systematic Reviews)

  • Cochrane Database of Systematic Reviews (EBMR, Ovid menu)

Synopses of Single Studies

  • ACP Journal Club (EBMR, Ovid menu)

Primary sources

Primary sources are single studies which have not been evaluated

Primary sources have their own hierarchy – see the pyramid below.

Match the publication type to the question being asked (Refer to the ‘Type of question table’ when choosing from this pyramid)

Single primary studies are found in the major medical, nursing and allied health databases - Medline (EBSCO or Ovid) and PubMed (the free version of Medline), Embase, CINAHL, PsycINFO.