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Evidence Based Medicine Resources

Evidence Based Medicine is about finding answers to clinical problems, based on the best available evidence from clinical research. There are a number of resources available for finding evidence to support a clinical decision, and it can be confusing knowing just where to start. Haynes' '4S' approach(1) provides guidance by encouraging use of the most evolved information service possible.

Haynes 4S model

SYSTEMS  - computerised decision support systems

SYNOPSES  - evidence-based journal abstracts

SYNTHESES  - Cochrane reviews

STUDIES  - original published articles in journals

Haynes' 4S model categorises resources in terms of a hierarchy, with original studies at the base, syntheses (or systematic reviews) on the level above, followed by synopses, and finally systems, representing the most evolved of the evidence based medicine sources currently available. It is suggested to "begin your search for best evidence by looking at the highest-level resource available for the problem that prompts your search." (2)  

Not to be confused with the recognised 'levels of evidence' (3), the '4S' model presents a hierarchy of the resources available to locate best evidence. Although gold standard evidence (eg. a systematic review of randomised controlled trials) falls into the bottom strata of Haynes' 4S model, it is likely that such evidence would be the basis upon which the more evolved information resources, such as synopses, have been developed. By using the highest-level resource to locate best evidence the busy clinician is saved the burden of locating, and appraising individual studies from which to make an informed decision.

Evidence-based resources available to you as a student or staff member of The University of Newcastle, are listed below under the '4S' categories.

Systems

"Systems" refers to computerised decision support systems, but these are still rather hypothetical. Haynes suggests that a perfect electronic clinical information system would automatically integrate and link all important and relevant research evidence with electronic medical records. Whilst they don't yet merge with patient records, there are some emerging tools which at least potentially could contribute to such systems.

Synopses

Synopses should provide a quick summary with enough information to make a clinical decision. Synopses of recent research, both primary research and review articles, are published in the form of 1 page structured abstracts. Journals that publish such commentaries, include:

Syntheses

Syntheses summarise what is known about a topic, and should be referred to if more detail is needed or no synopsis is available.  They are based on rigorous searches for evidence, explicit scientific reviews of the studies uncovered in, and systematic assembly of the evidence to provide as clear a signal about the effects of a health care intervention as the evidence will allow.

Studies

You will need to search for original studies if systems, synopses or syntheses are not available.

 

References:
1. Haynes RB. Of studies, syntheses, synopses, and systems: the "4S" evolution of services for finding current best evidence. ACP Journal Club 2001;134(2):A11-3.
2. Strauss SE, Richardson WS, Glasziou P, Haynes RB. Evidence-based medicine: how to practice and teach EBM. 3rd ed. Edinburgh: Elsevier; 2005. p.33
3. National Health & Medical Research Council.  Appendix B, Designation of Levels of Evidence.  A guide to the Development, Implementation, Evaluation of Clinical Practice Guidelines.  Commonwealth of Australia, 1999.

 

Acknowledgements:
This web page has been modelled on those produced by Ruth Sladek of the RGH Medical Library at the Australian Centre for Evidence Based Clinical Practice, Miranda Morfey, Medical Librarian at the Gus Fraenkel Medical Library, Flinders University, and Lisa Bradley, Life Sciences Librarian, Australian National University.