Parallax View

Parallax: The apparent displacement of an object by a change in the position from which it is viewed. Due to significant variation in clinical practice, multiple societies and commissioned groups have developed and published clinical practice guidelines. Potentially, the guidelines will standardize clinical practice and thereby improve patient outcome, increase cost-effectiveness and serve as an educational tool. Ineffective guidelines may waste resources or worse, harm patients (1,2). But how do we explain the phenomenon when two groups address the same clinical practice question and make different treatment recommendations (3)? Did one of the groups draw erroneous conclusions? Practice guidelines, according to the Institute of Medicine, are defined as ‘‘systematically developed statements’’ in which the recommendations are the result of the stated methodological process. The assumption is that all guidelines are based on the best available evidence (4). However, there are many methods by which one can develop guidelines and each has its strengths and its weakness. Consider Evidence Based Medicine (EBM) as a methodology for guideline development. EBM recommendations are based on the best available external clinical evidence. Emphasis is placed on systematic observation, rules of evidence, and critical interpretation of the literature with less value placed on physiologic principles and clinical experience. EBM emphasizes empirical knowledge (studies) over rational thinking (5). The Randomized Controlled Trial (RCT) is considered the gold standard as RCTs demonstrate efficacy of treatment for the ‘‘average’’ randomized patient chosen from a carefully selected group of study patients. If no randomized trial has been performed, the next best external evidence is used. There may be huge gaps in the evidence. The reliance on published studies means that the EBM methodology is susceptible to the publication bias against ‘‘negative’’studies. Another method by which to develop a guideline is consensus (2). Consensus methods attempt to assess the extent of agreement and resolve disagreement. In contrast to EBM methodology, expert opinion without explicit critical appraisal, as well as conclusions based on physiology or bench research are included as part of the basis for recommendations. Although some guidelines are not commissioned by a professional organization, to most people, the term ‘‘consensus guidelines’’ implies that the work has arisen from a committee of experts selected by the leaders of a society, and that the document has been thoroughly vetted to assure that conclusions are unbiased and appropriate. There is an assumption that a specialty society oversaw the development of the guidelines to ensure that the recommendations reflected the consensus of more than just the few authors (6). Two different groups of clinical toxicologists have developed a practice guideline regarding the indications for administration of Ipecac. The first Ipecac guideline (Position Statement) was developed by the American Academy of Clinical Toxicology (AACT) and European Association of Poison Centres and Clinical Toxicologists (EAPCCT), published in 1997 and updated in 2004 (7,8). The second Ipecac guideline, developed by a Consensus Panel, is published in this issue of the Journal (9). The two guidelines differ in recommended indications for the administration of Ipecac. The two guidelines originated as a result of different perceived needs, although both guidelines were developed in response to an observed variation in clinical practice. In 1993, the Presidents of the AACT and EAPCCT noted the variation in the clinical practice of GI decontamination and developed an EBM methodology to write Position Statements. All relevant scientific literature was reviewed. Clinical and experimental studies were given precedence over case reports. Abstracts and expert opinion were not considered. A draft was then produced and peer-reviewed by an international group of clinical toxicologists chosen by the two societies. The guidelines were then discussed at open forums at the NACCT and the EAPCCT International Congress. Peer review and approval by both Boards of Trustees were required. These guidelines were evidence based and did not rely on consensus opinion. These guidelines were intended for the inhospital treatment of the poisoned patient (7). In 2001, following institution of a toll-free 800 number for all US Poison Centers, Public Health Analysts noted the wide variation in prehospital recommendations between Poison Centers. Due to the potential for Poison Centers to answer each others’ calls, as well as the potential to confuse the public, a seven member committee was appointed and supported by the federal government grants to develop consensus guidelines. The American Association of Poison Centers (AAPCC), AACT, and American College of Medical Toxicology (ACMT) nominated members. Additional members were subsequently added by the committee itself. The Consensus Panel used a modified Delphi process. In the Delphi process, opinions are grouped or ranked,