E839C linical practice guidelines, which are systematically developed statements aimed at helping people make clinical, policy-related and system-related decisions, 1,2 frequently vary widely in quality. 3,4 A strategy was needed to differentiate among guidelines and ensure that those of the highest quality are implemented.An international team of guideline developers and researchers, known as the AGREE Collaboration (Appraisal of Guidelines, Research and Evaluation), was established to create a generic instrument to assess the process of guideline development and reporting of this process in the guideline. Based on rigorous methodologies, the result of the collaboration's efforts was the original AGREE instrument, which is a 23-item tool comprising six quality-related domains that was released in 2003 (www.agreetrust.org).As with any new assessment tool, ongoing development was required to improve its measurement properties, usefulness to a range of stakeholders and ease of implementation. Over the years, a number of issues were identified. For example, the original four-point response scale used to answer each item of the AGREE instrument is not in compliance with methodologic standards of health measurement design. This noncompliance threatens the performance and reliability of the instrument. 5 In addition, data on the usefulness of the AGREE items has never been gathered systematically from the perspectives of different groups of users. Further, we were interested in identifying strategies to make the evaluation process more efficient, such as reducing the number of items or the number of required raters, while ensuring the instrument was reliable and valid. Therefore, an exploration of the role of shorter versions of the AGREE instrument, comprising fewer items that are tailored to the unique priorities of different stakeholders, was warranted. Finally, there was a need to establish the fundamentals of construct validity -in other words, whether the AGREE items could measure what they purport to measure, and that is variability in quality of practice guidelines.
Redesign of AGREEIn response to these issues, the AGREE Next Steps Consortium was established and undertook two studies.6,7 As part of the first study, the consortium introduced a new seven-point response scale and evaluated its performance and measurement properties, analyzed the usefulness of the AGREE items for decisions made by different stakeholders, and systematically elicited stakeholders' recommendations for changes to the AGREE items and domains. 6 In the second study, the consortium evaluated the construct validity of the tool and designed and evaluated new supporting documentation aimed at facilitating efficient and accurate use of the tool.
7The following key findings emerged from the two studies:• Ratings of the quality of the AGREE domains are good predictors of outcomes associated with implementation of guidelines.
6• Participants (i.e., guideline developers or researchers, policy-makers, and clinicians) evaluated AGREE items and dom...