The validity and utility of the Cutaneous Disease Area and Severity Index (CDASI) as a clinical outcome instrument in dermatomyositis: a comprehensive review

Abstract Introduction Validated outcome measures are paramount in the assessment of disease progression and evaluation of new therapeutics in clinical trials. Dermatomyositis (DM) is an autoimmune disease that is frequently refractory to current therapies and warrants the development of new treatments. The Cutaneous Disease Area and Severity Index (CDASI) was developed in 2008 in response to a need for a reliable, validated measure of skin disease activity and damage for use in clinical trials and longitudinal monitoring of disease progression. Methods The literature was searched for all studies validating and utilizing the CDASI between 2008 and October 2018 using searches in PubMed. Studies pertaining to validation of the CDASI, correlation with quality of life, use in the evaluation of current therapies and ongoing trials, as well as relationships to biomarkers were included in this review. Results The CDASI was found to have intra- and inter-rater reliability, validity, reproducibility, sensitivity to clinical changes, and ease of use. It has been shown to correlate with quality of life as measured by the Skindex-29 outcome measure. The CDASI activity score has additionally been shown to correlate significantly with IFN-β, a key cytokine in DM pathogenesis. Conclusion The CDASI is a validated measure of dermatomyositis disease and has been shown to be an effective outcome instrument in clinical trials.