Development and validation of a comprehensive acne severity scale

• Published in: Journal of cutaneous medicine and surgery Vol. 11; no. 6; p. 211
• Main Authors: Tan, Jerry K L, Tang, Jing, Fung, Karen, Gupta, Aditya K, Thomas, D Richard, Sapra, Sheetal, Lynde, Charles, Poulin, Yves, Gulliver, Wayne, Sebaldt, Rolf J
• Format: Journal Article
• Language: English
• Published: United States 01.11.2007
• Subjects: Acne Vulgaris - diagnosis; Acne Vulgaris - pathology; Acne Vulgaris - therapy; Back; Canada; Face; Follow-Up Studies; Health Surveys; Humans; Retrospective Studies; Severity of Illness Index; Thorax; Treatment Outcome; Canada
• ISSN: 1203-4754
• DOI: 10.2310/7750.2007.00037

Although more than 25 acne grading systems exist, only 2 are inclusive of truncal acne. There is neither a gold standard nor a consistently used standardized system. Our purpose was to develop and validate an acne grading system incorporating severity at the face, chest, and back. We developed a comprehensive acne severity scale (CASS) by modifying a preexisting facial acne scale, the Investigator Global Assessment, to include truncal acne. The validity and responsiveness of CASS grades were correlated with Leeds scores at baseline and after 6 months of standard acne treatment. Spearman correlations were significant between Leeds and CASS grades for the face (0.823), chest (0.854), and back (0.872), respectively (p < .001). After 6 months of therapy, changes in these scores were also significantly correlated (p < .001) at all three sites. Concurrent validity of CASS is demonstrated by a very strong correlation with Leeds grading. CASS is simpler to use than the Leeds system and more appropriate for translation of research trial results to clinical practice.