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Commentary| Volume 64, ISSUE 12, P1272-1274, December 2011

Strength of evidence and handling uncertainty: practical considerations and general observations

Published:September 02, 2011DOI:https://doi.org/10.1016/j.jclinepi.2010.11.024
      It is an interesting conundrum that while the objective of undertaking any research should be to inform clinical practice in some manner, that we should then have so much difficulty in weighing the results of such research and deciding how far it should, or should not, guide practice. The principles of evidence-based medicine (EBM) are now irrevocably imbedded in many health care systems throughout the world. Sackett et al. [
      • Sackett D.L.
      • Rosenberg M.C.
      • Gray J.A.
      • Haynes R.B.
      • Richardson W.S.
      Evidence based medicine: what it is and what it isn’t.
      ] in a much-quoted article outlined what EBM “is,” and in recognizing the practicalities involved of using such an approach, perhaps just as importantly outlined what it “isn’t.” However, even with a cursory knowledge of EBM, it soon becomes apparent that in trying to apply evidence generated from studies to clinical situations we are not dealing with certainties, rather, with varying degrees of uncertainty. In many situations, information is incomplete and decision makers must wrestle with an irreducible core of uncertainty. How we take account of and express that uncertainty within the specific context of care is the crux of the issue.
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      References

        • Sackett D.L.
        • Rosenberg M.C.
        • Gray J.A.
        • Haynes R.B.
        • Richardson W.S.
        Evidence based medicine: what it is and what it isn’t.
        BMJ. 1996; 312: 71-72
        • Atkins D.
        • Eccles M.
        • Flottorp S.
        • Guyatt G.H.
        • Henry D.
        • Hill S.
        • et al.
        Systems for grading the quality of evidence and the strength of recommendations I: critical appraisal of existing approaches. The GRADE Working Group.
        BMC Health Serv Res. 2004; 4: 38
        • Atkins D.
        • Briss P.A.
        • Eccles M.
        • Flottorp S.
        • Guyatt G.H.
        • Harbour R.T.
        • et al.
        Systems for grading the quality of evidence and the strength of recommendations II: pilot study of a new system.
        BMC Health Serv Res. 2005; 5: 25
        • Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) Working Group
        Grading quality of evidence and strength of recommendations.
        BMJ. 2004; 328: 1490-1494
        • Guyatt G.H.
        • Oxman A.D.
        • Kunz R.
        • Vist G.E.
        • Falck-Ytter Y.
        • Schünemann H.J.
        • et al.
        What is “quality of evidence” and why is it important to clinicians?.
        BMJ. 2008; 336: 995-998
        • Guyatt G.H.
        • Oxman A.D.
        • Kunz R.
        • Jaeschke R.
        • Helfand M.
        • Liberati A.
        • et al.
        Incorporating considerations of resources use into grading recommendations.
        BMJ. 2008; 336: 1170-1173
        • Jaeschke R.
        • Guyatt G.H.
        • Dellinger P.
        • Schünemann H.
        • Levy M.M.
        • Kunz R.
        • et al.
        Use of GRADE grid to reach decisions on clinical practice guidelines when consensus is elusive.
        BMJ. 2008; 337: a744
      1. List of GRADE working group publications and grants. Available at http://www.gradeworkinggroup.org/publications/index.htm. Accessed July 12, 2011.

      2. Organizations that have endorsed or that are using GRADE. Available at http://www.gradeworkinggroup.org/society/index.htm. Accessed 12 July 2011.

        • Guyatt G.H.
        • Oxman A.D.
        • Vist G.E.
        • Kunz R.
        • Falck-Ytter Y.
        • Alonso-Coello P.
        • et al.
        GRADE: an emerging consensus on rating quality of evidence and strength of recommendations.
        BMJ. 2008; 336: 924-926
        • Gray J.A.M.
        Evidence-based medicine: how to make health policy and management decisions.
        Churchill Press, London, UK1997
        • Croft A.M.
        Malaria: prevention in travellers. Clinical Evidence.
        BMJ Publishing Group, 2010 (Available at) (Accessed July 12, 2011)
        • Halleck M.
        • Cheson B.D.
        • Catovsky D.
        • Calgaris-Cappio F.
        • Dighiero G.
        • Dohner H.
        • et al.
        Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on Chronic Lymphocytic Leukemia updating the National Cancer Institute-Working Group 1996 guidelines.
        Blood. 2008; 111: 5446-5456
        • Concato J.
        • Shah N.
        • Horwitz R.I.
        Randomised controlled trials, observational studies, and the hierarchy of research designs.
        N Eng J Med. 2000; 342: 1887-1892
        • Kavanagh B.P.
        The GRADE system for rating clinical guidelines.
        PLoS Med. 2009; 6: e1000094
        • Ansari M.T.
        • Tsertsvadze A.
        • Moher D.
        Grading quality of evidence and strength of recommendations: a perspective.
        PLoS Med. 2009; 6: e1000151
        • Owens D.K.
        • Lohr K.N.
        • Atkins D.
        • Treadwell J.R.
        • Reston J.T.
        • Bass E.B.
        • et al.
        AHRQ series paper 5: grading the strength of a body of evidence when comparing medical interventions—agency for healthcare research and quality and the effective health-care program.
        J Clin Epidemiol. 2010; 63: 513-523