%0 Journal Article
%T Systems for grading the quality of evidence and the strength of recommendations I: Critical appraisal of existing approaches The GRADE Working Group
%A David Atkins
%A Martin Eccles
%A Signe Flottorp
%A Gordon H Guyatt
%A David Henry
%A Suzanne Hill
%A Alessandro Liberati
%A Dianne O'Connell
%A Andrew D Oxman
%A Bob Phillips
%A Holger Sch¨¹nemann
%A Tessa Edejer
%A Gunn E Vist
%A John W Williams
%A The GRADE Working Group
%J BMC Health Services Research
%D 2004
%I BioMed Central
%R 10.1186/1472-6963-4-38
%X Six prominent systems for grading levels of evidence and strength of recommendations were selected and someone familiar with each system prepared a description of each of these. Twelve assessors independently evaluated each system based on twelve criteria to assess the sensibility of the different approaches. Systems used by 51 organisations were compared with these six approaches.There was poor agreement about the sensibility of the six systems. Only one of the systems was suitable for all four types of questions we considered (effectiveness, harm, diagnosis and prognosis). None of the systems was considered usable for all of the target groups we considered (professionals, patients and policy makers). The raters found low reproducibility of judgements made using all six systems. Systems used by 51 organisations that sponsor clinical practice guidelines included a number of minor variations of the six systems that we critically appraised.All of the currently used approaches to grading levels of evidence and the strength of recommendations have important shortcomings.In 1979 the Canadian task Force on the Periodic Health Examination published one of the first efforts to explicitly characterise the level of evidence underlying healthcare recommendations and the strength of recommendations [1]. Since then a number of alternative approaches has been proposed and used to classify clinical practice guidelines [2-28].The original approach used by the Canadian Task Force was based on study design alone, with randomised controlled trials (RCTs) being classified as good (level I) evidence, cohort and case control studies being classified as fair (level II) evidence and expert opinion being classified as poor (level III) evidence. The strength of recommendation was based on the level of evidence with direct correspondence between the two; e.g. a strong recommendation (A) corresponded to there being good evidence. A strength of the original Canadian Task Force approach was that
%K evidence-based health care
%K levels of evidence
%K practice guidelines
%K strength of recommendation
%K systematic reviews
%U http://www.biomedcentral.com/1472-6963/4/38