Nonconformity in the clinical practice guidelines for subclinical Cushing's syndrome: which guidelines are trustworthy?

Objective: This study aimed to systematically evaluate the quality of clinical practice guidelines (CPGs) and to compare their recommendations for managing subclinical Cushing's syndrome (SCS) to assist practitioners in making rapid clinical decisions. Design and methods: SCS management guidelines were retrieved from electronic databases. The Appraisal of Guidelines Research and Evaluation II (AGREE-II) tool and the Institute of Medicine (IOM) criteria were used to evaluate the quality of the selected guidelines. In addition, we further compared recommendations, cited references and levels of evidence between the SCS management guidelines. Results: We included five guidelines that were obtained through the literature selection process. On the basis of the AGREE-II and IOM criteria, none of the selected guidelines were satisfactory in all aspects. However, the Italian Association of Clinical Endocrinologists (IACE) guidelines demonstrated slightly higher scores than did the other guidelines, so this guideline was recommended (with certain modifications for several domains). Regarding the content of the CPGs, we found considerable differences in the recommendations for managing SCS. These differences were derived from citation selection bias, evidence interpretation bias, differences in the composition of the guidelines' workgroups and the omission of guidelines for updating and externally reviewing the recommendations. Conclusions: There is generally poor guideline quality among different organisations, and remarkable differences exist in the recommendations for the same clinical subject. Therefore, future guideline development should be performed in strict accordance with the AGREE-II and IOM criteria.