During the course of a controlled clinical study the patients' facial acne was assessed using a 0–10 visual-tactile grading system and by lesion counting. In addition, black-and-white photographs and colour slides were taken at each patient visit and subsequently assessed by a panel of three dermatologists. Scores obtained from each method of assessment were subjected to statistical analysis and correlations between the techniques were evaluated.
We conclude that a well thought out clinical grading system is the best overall method as it provides a meaningful assessment with speed and reasonable accuracy.
A clinically meaningful objective assessment of the effect of treatment on acne vulgaris is important when evaluating the relative merits of therapeutic substances in this condition. The assessment techniques usually employed are lesion counting, grading systems and photographic methods and each has positive and negative features. Lesion counting would appear to offer an objective measurement but it is a relatively tedious and lengthy process and a 50% reduction of certain lesions is not always reflected by a 50% improvement in the patient's appearance. Clinical grading systems which are sophisticated enough to truly reflect disease severity are probably more meaningful than lesion counting but may be suspected of lacking objectivity. Photographic methods allow a permanent record to be kept but do not allow palpation of the lesions.
We felt it to be of value to compare these methods of assessment despite their obvious qualitative differences.