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Evidence-Based Medicine: 6S Hierarchy of EBM Resources

This is a libguide for praticing evidence-based medicine.

Categories of EBM resources

The previous pages help you decide what type of evidence is likely to answer your question, however, to know where to search for the evidence, you need to understand how evidence is organized into categories of EBM resources.

 

 

The 6S Hierarchy of Evidence Based Resources is a useful model for guiding clinical decision making.The model proposes 6 layers of evidence sources. The search for evidence based resources should begin at the highest possible layer. The categories of EBM resources described here are corresponding to layers of 6S model of EBM resources.

 

 

 

                  

DiCenso A, Bayley L, Haynes RB (2009). Accessing pre-appraised evidence: fine-tuning the 5S model into a 6S model. Evidence-Based Nursing, 12(4),99-101.

                                                                                                                                                     

From a practical point of view, resources can be viewed in 3 broad categories: summaries and guidelines, pre-appraised research and non-appraised primary studies.

Categories of EBM Resources

Category                         Description Examples
Summaries and guidelines Online summary provides the body of evidence at a topic-level (not limited to a question, intervention, or outcome); Databases of clinical practice guidelines with recommendations for clinical decision making

ACP Smart Medicine & AHFS DI® Essentials™

UpToDate

Natural Medicine

Pre- appraised resources Synopses of systematic reviews, Systematic reviews and Synopses of studies provide with assessment of original study or summary of a number of studies.

Cochrane

ACP Journal Club (now is Annals of Internal Medicine)

BMJ EvidenceAlerts

McMaster PLUS

Non-appraised primary studies All primary Studies with no preappraisal.

PubMed (MEDLINE)

MEDLINE - Ovid

CINAHL

Embase - Ovid


Federated search (or Meta search) engines allow searching for evidence across multiple resources (all levels of the 6S pyramid) at the same time. These tools retrieve evidence from summaries and preappraised and nonpreappraised research, and organize the results accordingly: try these EBM search engines!

TRIP

SumSearch 2

Epistimonikos

ACCESSSS