For each outpatient gastrointestinal topic, the relevant guidelines published by the American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), American Society for Gastrointestinal Endoscopy (ASGE), American Association for the Study of Liver Diseases (AASLD), and European Association for the Study of the Liver were reviewed. These guidelines were supplemented by searches within PubMed by using the terms described in the topics of interest and focusing on QI specific reviews and studies.
For specific gastrointestinal society guideline or position statement recommendations, a quality of evidence grade was reported whenever possible, which was based on an adaptation of the Standardized Guidelines of the Practice Committee of the AASLD (grade definition: grade A: homogeneous evidence from multiple well-designed randomized [therapeutic] or cohort [descriptive] controlled trials, each involving a number of participants to be of sufficient statistical power; grade B: evidence from at least 1 large well-designed clinical trial with or without randomization, from cohort or case-control analytical studies, or well-designed meta-analysis; grade C: evidence based on clinical experience, descriptive studies, or reports of expert committees; grade D: not rated).[25,26] Other grading systems used in the literature were translated into these grades and denoted by an asterisk (*). When conflicting levels of evidence were reported by different gastrointestinal societies, the most recent and updated level of evidence for the recommendation was used. When a direct translation was not possible, the quality of evidence was described rather than graded.
Clin Gastroenterol Hepatol. 2012;10(12):1305-1314. © 2012 AGA Institute