Development and Validation of a Composite Skin Quality Scale

Abstract

Abstract Background The increasing demand for skin quality interventions in aesthetic medicine underscores the necessity for objective, evidence-based assessment tools that may be used to evaluate novel interventions or devices. Objectives To develop and validate a 5-point photo-numeric rating scale for assessing overall skin quality, including radiance, color evenness, and smoothness. Methods The IBSA (Institut Biochimique SA) Composite Skin Quality Scale was developed and underwent live validation with 88 real-world patients, chosen to encompass a broad spectrum of skin qualities and Fitzpatrick skin types. Scale validation was performed by board-certified plastic surgeons and dermatologists over 2 rounds, 2 weeks apart. Reliability was assessed via intrarater and interrater agreements, utilizing weighted kappa statistics and intraclass correlation coefficient (ICC). The scale's ability to discern a clinically relevant 1-grade difference was evaluated with 72 photo pairs. Results Combined intrarater reliability results showed weighted kappa values of 0.812 (right side) and 0.815 (left side), and an ICC of 0.903 for both sides, indicating almost perfect agreement. Interrater reliability ranged from substantial to almost perfect, with kappa coefficients between 0.654 and 0.853, and ICCs from 0.657 to 0.855 across all rater pairs in both rounds. The ability to detect a clinically relevant 1-point difference using the scale was established. Conclusions Integrating various key aspects of skin quality, the IBSA Composite Skin Quality Scale is a clinically relevant and highly reliable tool, suitable for skin assessment in clinical studies of new aesthetic technologies and products.