Reliability of Clinician Erythema Assessment grading scale

Background: Facial erythema is a clinical hallmark of rosacea and often causes social and psychological distress. Although facial erythema assessments are a common endpoint in rosacea clinical trials, their reliability has not been evaluated. Objective: The objective of this study was to evaluate the inter-and intrarater reliability of the Clinician's Erythema Assessment (CEA), a 5-point grading scale of facial erythema severity. Methods: Twelve board-certified dermatologists, previously trained on use of the scale, rated erythema of 28 rosacea subjects twice on the same day. Interrater and intrarater agreement was assessed with the intraclass correlation and k statistic. Results: The CEA had high interrater reliability and good intrarater reliability with an overall intraclass correlation coefficient (ICC) for session 1 and session 2 of 0.601 and 0.576, respectively; the overall weighted k statistic for session 1 and session 2 was 0.692. Limitations: Raters were experienced dermatologists and there may be a risk of recall bias. Conclusion: When used by trained raters, CEA is a reliable scale for measuring the facial erythema of rosacea.