RT Journal A1 Khan A, Baddour LM, Tleyjeh IM T1 Evaluation of idsa clinical practice guidelines: A call to re-grade underlying evidence JF Archives of Internal Medicine JO Archives of Internal Medicine YR 2011 FD August 8 VO 171 IS 15 SP 1401 OP 1404 DO 10.1001/archinternmed.2011.346 UL http://dx.doi.org/10.1001/archinternmed.2011.346 AB Lee and Vielemeyer1 reported that approximately one-half of the IDSA guidelines were based on low-level evidence that was largely derived from expert opinion. Their findings concur with our evaluation of the IDSA guidelines, which has been recently published in Clinical Infectious Diseases.2 The process of grading evidence on the basis of hierarchy of study design has been the subject of criticism. We agree with Lee and Vielemeyer1 that it is time that a standard system for synthesizing evidence should be adopted. A GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system has been suggested to provide a better approach to synthesize guidelines.3 In this system, the evidence would not be entirely dependent on study design but would allow value judgments in evaluating evidence in a transparent manner. In fact, IDSA decided in 2008 to adopt a GRADE system for all new guidelines and updates; the first guidelines using this system would appear in 2011.4