Development and validation of a photonumeric scale for evaluation of facial fine lines

Background: A validated scale is needed for objective and reproducible comparisons of facial fine lines before and after treatment in practice and clinical studies. Objective: To describe the development and validation of the 5-point photonumeric Allergan Fine Lines Scale. Methods: The Allergan Fine Lines Scale was developed to include an assessment guide, verbal descriptors, morphed images, and real subject images for each scale grade. The clinical significance of a 1-point score difference was evaluated in a review of multiple image pairs representing varying differences in severity. Interrater and intrarater reliability was evaluated in a live subject validation study (N = 289) completed during 2 sessions occurring 3 weeks apart. Results: A score difference of ≥1 point was shown to reflect a clinically significant difference (mean [95% CI] absolute score difference, 1.06 [0.92-1.21] for clinically different image pairs and 0.50 [0.38-0.61] for not clinically different pairs). Intrarater agreement between the 2 live subject validation sessions was almost perfect (weighted kappa = 0.85). Interrater agreement was substantial during the second rating session (0.76, primary end point). Conclusion: The Allergan Fine Lines Scale is a validated and reliable scale for physician rating of severity of superficial fine lines.