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Of studies, summaries, synopses, and systems: the “4S” evolution of services for finding current best evidence
  1. R. Brian Haynes, MD, PhD
  1. McMaster University
    Hamilton, Ontario, Canada

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Practical resources to support evidence-based healthcare decisions are rapidly evolving. New and better services are being created through the combined forces of increasing numbers of clinically important studies, increasingly robust evidence synthesis and synopsis services, and better information technology and systems. The need for these resources is being spurred by demands for higher quality at lower cost from health services, but the impact of better information resources is being blunted by noisy pretenders, promising “the earth” but yielding just the dirt. Providers and consumers of evidence-based health care can help themselves to current best evidence by recognising and using the most “evolved” information services for the topic areas of concern to them.

The figure provides a “4S” hierarchical structure, with original “studies” at the base, “syntheses” (systematic reviews) of evidence just atop the base, then “synopses” of studies and syntheses next up, and the most evolved evidence-based information “systems” at the top. Information seekers should begin looking at the highest level resource available for the problem that prompted their search.

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“4S” levels of organisation of evidence from research


A perfect evidence-based clinical information system would integrate and concisely summarise all relevant and important research evidence about a clinical problem and would automatically link, through an electronic medical record, a specific patient’s circumstances to the relevant information. The user would then consult the system—in fact, be reminded by the system—whenever the patient’s record was reviewed. The information contained in the system would be based on an explicit review process for finding and evaluating new evidence as it is published and then reliably updated whenever important new research evidence became available. Thus, clinicians and patients could always have the benefit of the current best evidence. The system would not tell decision makers what to do—those judgments would require integration of the system’s …

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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), Cochrane Library (reviewer and former board member and Cochrane Centre director), Clinical Evidence (advisory board), and PubMed Clinical Queries (developer). These resources are used to illustrate the concepts in the paper; there are other, and perhaps better, examples.

  • A previous version of this editorial was published in OpenUrlPubMed and OpenUrlFREE Full Text

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