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Of studies, syntheses, synopses, summaries, and systems: the “5S” evolution of information services for evidence-based healthcare decisions
  1. R Brian Haynes, MD, PhD
  1. McMaster University
 Hamilton, Ontario, Canada

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    Success in delivering evidence-based health care relies heavily on the ready availability of current best evidence about diagnosis, treatment, and prevention options for health disorders, ideally tailored to the characteristics and context of the individual patient or population and the resources of the provider. While existing information resources fall short of perfection, the past decade has seen considerable progress, and an attractive array of services is now available for many healthcare decisions. Providers and consumers of evidence-based health care can help themselves to the best current evidence by recognising the most “evolved” information services in the topic areas of concern to them.

    A “4S” model for the organisation of evidence-based information services, proposed several years ago,1 begins with original studies at the foundation; syntheses (that is, systematic reviews, such as Cochrane Reviews) at the next level up; then synopses (very brief descriptions of original articles and reviews, such as those that appear in the evidence-based journals); and the most evolved services, systems (such as computerised decision support systems that link individual patient characteristics to pertinent evidence) at the top.

    George Box, an industrial statistician, once pointed out that “All models are wrong, some are useful”,2 and so it is with the 4S model. Conceptually, this model has been useful for both describing and guiding the development of evidence-based information services, and it has also been wrong in oversimplifying the relationship of these services to original studies. In this editorial we add a layer to the model, namely, clinical topic summaries of evidence about all pertinent management options for a health condition, such as those included in Clinical Evidence and PIER. A second purpose of the editorial is to explore how the layers are relevant to clinical decisions in ways that may not be apparent in the model. …

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    • Conflict of interest statement: Brian Haynes has direct or indirect connections with many of the evidence-based resources used as examples above, including ACP Journal Club (editor), Evidence-Based Medicine (co-editor), Evidence-Base Nursing (coordinating editor), BMJUpdates+ (editor), The Cochrane Library (reviewer and former board member and Cochrane Centre director), Clinical Evidence (advisory board), PIER (evidence supplier), and PubMed Clinical Queries (developer). These resources are used to illustrate the concepts in the paper; there are other, and perhaps better, examples.