Cross-Cultural Adaptation and Validation of the Hong Kong-Chinese Version of Vocal Fatigue Index (VFI(HK)).

PURPOSE: This study aimed to cross-culturally adapt and validate the Hong Kong-Chinese version of the Vocal fatigue index (VFI(HK)). METHOD: The original English version of the Vocal fatigue index (VFI) was translated and adapted to the VFI(HK). A total of 206 subjects (87 in the Fatigue group and 119 in the Control group) completed the VFI(HK) and validity, reliability and receiver operating characteristic (ROC) were analysed. RESULT: The VFI(HK) exhibited satisfactory psychometric properties. It showed good content validity (scale-level content validity indices ≥ 0.842) and excellent internal consistency (Part 1: α = 0.945, Part 2: α = 0.914, Part 3: α = 0.951). Parts 1 and 2 of the questionnaire showed good construct validity (Part 1: t(204) = 5.743, P < 0.001; Part 2: t(204) = 5.049, P < 0.001). Test-retest reliability ranged from acceptable (Part 3: Ρ = 0.702) to good (Part 1: Ρ = 0.885, Part 2: Ρ = 0.827). ROC curves showed acceptable and close-to-acceptable intrinsic accuracies for Parts 1 (Aera under curve (AUC) = 0.712) and 2 (AUC = 0.694) respectively. Cutoff scores of 25 and 10 are suggested for Parts 1 and 2 respectively. CONCLUSION: The VFI(HK) is a valid and sensitive assessment tool. It may be adopted to identify individuals with vocal fatigue in the Hong Kong-Chinese population.