Objective: To identify and compare clinical practiceguideline appraisal instruments.

Methods: Appraisal instruments,defined as instruments intended to be used for guideline evaluation,were identified by searching MEDLINE (1966–99) using the MedicalSubject Heading (MeSH) practice guidelines, reviewing bibliographiesof the retrieved articles, and contacting authors of guidelineappraisal instruments. Two reviewers independently examined thequestions/statements from all the instruments and thematicallygrouped them. The 44 groupings were collapsed into 10 guidelineattributes. Using the items, two reviewers independently undertook acontent analysis of the instruments.

Results: Fifteen instruments were identified, and two were excludedbecause they were not focused on evaluation. All instruments weredeveloped after 1992 and contained 8 to 142questions/statements. Of the 44 items used for the content analysis,the number of items covered by each instrument ranged from 6 to 34.Only the instrument by Cluzeau and colleaguesincluded at least one item for each of the 10 attributes, andit addressed 28 of the 44 items. This instrument and that of Shaneyfelt et al. are the only instruments that have so far been validated.

Conclusions: A comprehensive, concise, and valid instrument could helpusers systematically judge the quality and utility of clinicalpractice guidelines. The current instruments vary widely inlength and comprehensiveness. There is insufficient evidenceto support the exclusive use of any one instrument, although theCluzeau instrument has received the greatest evaluation. Moreresearch is required on the reliability and validity of existingguideline appraisal instruments before any one instrument can becomewidely adopted.