Development and Validation of a Photonumeric Scale for Evaluation of Volume Deficit of the Hand

Abstract

BACKGROUNDA validated scale is needed for objective and reproducible comparisons of hand appearance before and after treatment in practice and clinical studies.OBJECTIVETo describe the development and validation of the 5-point photonumeric Allergan Hand Volume Deficit Scale.METHODSThe scale was developed to include an assessment guide, verbal descriptors, morphed images, and real-subject images for each grade. The clinical significance of a 1-point score difference was evaluated in a review of image pairs representing varying differences in severity. Interrater and intrarater reliability was evaluated in a live-subject validation study (N = 296) completed during 2 sessions occurring 3 weeks apart.RESULTSA score difference of ≥1 point was shown to reflect a clinically significant difference (mean [95% confidence interval] absolute score difference, 1.12 [0.99–1.26] for clinically different image pairs and 0.45 [0.33–0.57] for not clinically different pairs). Intrarater agreement between the 2 validation sessions was almost perfect (mean weighted kappa = 0.83). Interrater agreement was almost perfect during the second session (0.82, primary end point).CONCLUSIONThe Allergan Hand Volume Deficit Scale is a validated and reliable scale for physician rating of hand volume deficit.