Cross-cultural adaptation and psychometric properties of a Spanish-language version of the Vestibular Disorders Activities of Daily Living Scale (VADL-ES).

Abstract

BackgroundVestibular disorders affect mobility, independence, and quality of life. Culturally adapted assessment tools are essential for accurate evaluation and effective treatment in diverse populations.ObjectivesTo translate, culturally adapt, and evaluate the psychometric properties of the Vestibular Disorders Activities of Daily Living Scale (VADL) into European Spanish (VADL-ES).MethodsThe VADL was adapted following international cross-cultural guidelines. Psychometric testing included internal consistency (Cronbach's α), test-retest reliability (ICC), content validity (CVI), convergent validity with the Dizziness Handicap Inventory (DHI), and discriminant validity (ROC analysis, Youden index). Floor/ceiling effects, standard error of measurement (SEM), minimal detectable change (MDC₉₅), and structural validity (exploratory and confirmatory factor analysis) were also assessed.ResultsThe VADL-ES showed excellent internal consistency (α = 0.978), test-retest reliability (ICC = 0.988), strong correlation with the DHI (ρ = 0.768), and high content validity (S-CVI = 0.93). ROC analysis yielded an AUC = 0.988 with 100% specificity. Factor analysis confirmed a three-factor structure explaining 72% of variance. No floor or ceiling effects were observed; MDC95 was 0.91.ConclusionsThe VADL-ES is a valid and reliable instrument for assessing functional limitations in Spanish-speaking patients with vestibular disorders, enabling standardized evaluation and longitudinal monitoring in clinical and research settings.