Development and validation of a comprehensive acne severity scale.

Authors :: Tan JK
Tang J
Fung K
Gupta AK
Thomas DR
Sapra S
Lynde C
Poulin Y
Gulliver W
Sebaldt RJ
Source :: Journal of cutaneous medicine and surgery [J Cutan Med Surg] 2007 Nov-Dec; Vol. 11 (6), pp. 211-6.
Publication Year :: 2007
Abstract: Background: 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.<br />Purpose: Our purpose was to develop and validate an acne grading system incorporating severity at the face, chest, and back.<br />Methods: 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.<br />Results: 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.<br />Conclusion: 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.