The Global Rating Scale complements the AGREE II in advancing the quality of practice guidelines

Objective: To explore the role of a four-item Global Rating Scale (GRS) that could be used in place of the Appraisal of Guidelines, Research and Evaluation II (AGREE II).

Study design and setting: A mixed four-factor design was used (User Type, Evaluation Type, Clinical Topic, Guideline). Participants were asked to read and evaluate a guideline using both the AGREE II draft and GRS or GRS only and to complete a series of questions regarding overall guideline quality, adoption, utility, and acceptability.

Results: One GRS item varied as a function of User Type. Each item was a significant predictor of participants' outcome measures. All items were rated as useful by stakeholders. The GRS rating scores, outcome measures, and usefulness scores did not vary between the two Evaluation Type conditions. Correlations between the GRS and the outcome measures were stronger compared with those between the AGREE II draft and these measures.

Conclusion: Although the GRS is less sensitive than the AGREE II in detecting differences in guideline quality as a function of User Type, its items did predict important outcome measures related to guideline adoption. The GRS may play a role in guideline evaluation, although further study is warranted.