Validation of a Self-Administered Acne Severity Index in a Convenience Sample of Adults.

Background: Patients' perception of their acne severity may vary and not correlate well with objective clinical acne grading systems. A self-administered acne severity measure allowing patients to accurately assess their facial acne severity would be useful for tracking acne severity in survey research.

Objectives: To evaluate a novel Self-Administered Acne Severity Index (SAASI) for use in adult survey research.

Methods: Five hundred and ninety participants were recruited through Amazon Mechanical Turk, an online crowdsourcing platform. Participants rated 8 "gold standard" dermatologist-rated acne images subjectively and then with the SAASI. The SAASI consists of reference photographs and descriptive multiple-choice questions. Participants' subjective assessments of acne severity, photo-assisted ratings, and SAASI ratings were compared with the dermatologists' ratings.

Results: Three hundred and seventy-one participants met inclusion criteria. Participants' subjective impressions of acne severity agreed with the dermatologist ratings 73.2% of the time, compared to 67.1% with the photo-assisted ratings and 70.1% with the SAASI ratings. Light-skin images had 53% greater odds of being rated accurately than dark-skin images, and severe acne images were rated most accurately, followed by clear, mild, and moderate acne.

Conclusion: Participants' subjective acne severity ratings had moderate agreement with dermatologists' rating, and the SAASI provided a formal measure with the similar level of agreement. The SAASI was a more precise rating system than raters by themselves, and improved participants' ability to rate moderate acne. Further research may help delineate the reproducibility of these results in diverse patient populations. At present, the SAASI may facilitate acne survey research by providing a simple, formal instrument for severity assessment.