By Mike McEvoy
Published guidelines are intended to assist practitioners in providing the best possible care to patients. Many assume that guidelines are supported by high level evidence and hence, are likely to assure optimal outcomes when followed. Maybe not so, according to a study published in the January 2011 issue of the Archives of Internal Medicine. In this study, the authors reviewed the quality of evidence behind 41 guidelines issued by the Infectious Diseases Society of America (ISDA) between 1994 and 2010. Half (50%) of the recommendations were based on level III evidence only (expert opinion). The authors note that other researchers had similar findings in reviews of American College of Cardiology and American Heart Association Guidelines (48% based on level III or expert opinion only).
This serves as a warning to providers that published guidelines may not always be supported by high-quality evidence and should not be relied on to replace critical thinking in practice.