Navigating the landscape of core outcome set development in dermatology.

The development of core outcome sets (COSs; ie, a minimum set of core outcomes that should be measured and reported in all trials or in clinical practice for a specific condition) in dermatology is increasing in pace. A total of 44 dermatology-related COS projects have been registered in the online Core Outcome Measures in Effectiveness Trials database (http://www.comet-initiative.org/studies/search) and include studies on 26 different skin diseases. With the increasing number of COSs in dermatology, care is needed to ensure the delivery of high-quality COSs that meet quality standards when using state-of-the-art methods. In 2015, the Cochrane Skin-Core Outcome Set Initiative (CS-COUSIN) was established. CS-COUSIN is an international, multidisciplinary working group aiming to improve the development and implementation of COSs in dermatology. CS-COUSIN has developed guidance on how to develop high-quality COSs for skin diseases and supports dermatology-specific COS initiatives. Currently, 17 COS development groups are affiliated with CS-COUSIN and following standardized COS development processes. To ensure successful uptake of COSs in dermatology, researchers, clinicians, systematic reviewers, guideline developers, and other stakeholders should use existing COSs in their work.