A Comprehensive Critique and Review of Published Measures of Acne Severity

Acne vulgaris is a dynamic, complex condition that is notoriously difficult to evaluate. The authors set out to critically evaluate currently available measures of acne severity, particularly in terms of suitability for use in clinical trials.

A systematic review was conducted to identify methods used to measure acne severity, using MEDLINE, CINAHL, Scopus, and Wiley Online. Each method was critically reviewed and given a score out of 13 based on eight quality criteria under two broad groupings of psychometric testing and suitability for research and evaluation.

Twenty-four methods for assessing acne severity were identified. Four scales received a quality score of zero, and 11 scored ≤3. The highest rated scales achieved a total score of 6. Six scales reported strong inter-rater reliability (ICC>0.75), and four reported strong intra-rater reliability (ICC>0.75). The poor overall performance of most scales, largely characterized by the absence of reliability testing or evidence for independent assessment and validation indicates that generally, their application in clinical trials is not supported.

This review and appraisal of instruments for measuring acne severity supports previously identified concerns regarding the quality of published measures. It highlights the need for a valid and reliable acne severity scale, especially for use in research and evaluation. The ideal scale would demonstrate adequate validation and reliability and be easily implemented for third-party analysis. The development of such a scale is critical to interpreting results of trials and facilitating the pooling of results for systematic reviews and meta-analyses.