re Lyme: http://www.lymedisease.org/news/lymepolicywonk/280.html OR in general: Infectious Disease Treatment Guidelines Weakened By Paucity of Scientific Evidence http://www.medscape.com/viewarticle/712341 (anyone can register to read this, by the way) Daniel M. Keller, PhD Excerpts: November 13, 2009 (Philadelphia, Pennsylvania) — Two separate analyses presented here at the Infectious Diseases Society of America (IDSA) 47th Annual Meeting revealed that most of the society's treatment guidelines are based on expert opinion, nonrandomized trials, and case studies. Only about 15% of the guidelines are supported by randomized controlled trials (RCTs), considered the highest level of evidence. Nonetheless, more than 40% of the guidelines' recommendations were classified as class A, the strongest level of treatment recommendation, according to Dong Lee, MD, and colleagues from the Division of Infectious Diseases and HIV Medicine at Drexel University College of Medicine in Philadelphia, Pennsylvania. ..."Ideally, all should be [supported by] level I evidence," Dr. Lee said. "However, a class A recommendation was supported by level I evidence only in 25% [of cases]." The rest were based on level II (40%) or level III (35%) evidence. Of all the guidelines evaluated, a median of 41% of recommendations were class A, but level I evidence supported them only 14% of the time. ....Dr. Lee summarized his presentation, saying that of the 1408 guideline recommendations he reviewed, "more than half were based on level III evidence, which is from expert opinion or not supported by properly controlled trials. Level I evidence was only 15%." He said his study should help to point out where evidence is lacking and to suggest areas for further research. Physicians and trainees should not just look at guidelines, but should also examine the strength of the evidence on which they are based, he advised. "When clinicians are using the guidelines, they should not assume that they are all based on well-designed studies. . . . Clinicians should remain cautious when using current guidelines as the sole source for guiding patient care." ...A second presentation supported the findings of Lee and coworkers. Abdur Khan, MD, assistant consultant at King Fahad Medical City in Riyadh, Saudi Arabia, presented his results in a poster session. Of the 65 IDSA guidelines, encompassing 6667 recommendations, issued between March 1994 and July 2009, he and his colleagues evaluated the 44, comprising 4206 recommendations, that were posted on the IDSA Web site at the end of July. They, too, found that, overall, the strength of the recommendations did not correlate with the available evidence. Level I evidence was the basis for only 15% of the guidelines, which is in agreement with the findings that Lee and colleagues reported. Thirty percent of the evidence was level II. Neither of these studies received funding. Dr. Lee and Dr. Khan have disclosed no relevant financial relationships. Dr. Whitley reports being on the board of directors of Gilead Sciences and is a consultant for 3-V Biologics and Chimerix; his other consulting, review, advisory panel positions, investigator, or speaker honoraria relationships include Juvaris, Primus, Inhibitex, and JID. Infectious Diseases Society of America (IDSA) 47th Annual Meeting: Abstract 1324. presented November 1, 2009; Abstract LB-31, presented October 31, 2009.