Vocal Fatigue Index (VFI): Cross-Cultural Adaptation, Validation, and Cut-off Values of the Arabic Version.

Objective: This study aims to validate, cross-culturally, and linguistically adapt the Vocal Fatigue Index (VFI) into Arabic.

Study design: Cross-sectional study.

Methods: The VFI was translated into Arabic, reverse translated, and content validated. To assess its psychometric properties, 398 patients with voice disorders (199 males, 199 females, mean age=46.2 ± 15.0years) and 121 vocally healthy controls (57 males, 64 females, mean age=42.1 ± 6.9years) completed the VFI-Arabic. We calculated internal consistency and test-retest reliability using Cronbach's alpha and intraclass correlation (ICC) coefficients. Independent sample t tests determined mean factor score differences between groups, while receiver operator characteristic curves analyzed sensitivity, specificity, and cut-off scores for the three factors.

Results: The overall Cronbach's alpha was 0.95, across all factors combined, it was 0.68; and for factors 1, 2, and 3, it was 0.95, 0.91, and 0.91, respectively. Test-retest reliability for the subscales was excellent (ICC: 0.97, 0.91, 0.82 for factors 1, 2, and 3). Mean subscale scores were significantly higher in the voice-disordered group than in controls. The area under the curve for factors 1, 2, and 3 was 0.824, 0.759, and 0.646, respectively. Best cut-off scores were ≥14.5 (69.8% sensitivity, 83.1% specificity) for factor 1, ≥3.5 (66.3% sensitivity, 74.4% specificity) for factor 2, and ≥5.5 (60.1% sensitivity, 64.5% specificity) for factor 3.

Conclusion: The VFI-Arabic is a valid and reliable tool for identifying and quantifying vocal fatigue symptoms in Arabic speakers.