Evaluation of the Consistency of Global Acne Grading System and Acne Lesion Counting

Objective To evaluate the consistency of global acne grading system (GAGS) and acne lesion counting. Methods After training 3 dermatologists evaluated 60 acne patients by GAGS and skin lesion counting respectively in randomized order sequentially, and evaluated again 5 days later. Results The kappa-value of GAGS (consistency) was 0.675 among 3 different dermatologists, and 0.847 for the same desmatologist. The kappa-value among the 3 different dermatologists and the same dermatologist for the total lesion count was 0.426 and 0.413 respectively; for pustule count was 0.446 and 0.407 respectively. The kappa-value of total number of the inflammatory lesion counting was 0.429 for the 3 different dermatologists and the kappa-value was 0.4 for the other lesion countings. Conclusions The consistency of GAGS evaluated by 3 different dermatologists and the same dermatologist is satisfactory, and the consistency of total lesion counting and pustule counting is good. The consistency of other different types of lesion counting is not so good. After defining the criteria of erythema lesions, the consistency for total inflammatory count increases and decreases for total lesion counting.