Translation, Cultural Adaptation, and Validation of the Vietnamese Version of the Vocal Fatigue Index

Abstract

Objectives: The Vocal Fatigue Index (VFI) is widely used to identify vocal fatigue, but no Vietnamese version exists. This study aimed to translate the VFI into Vietnamese and evaluate its reliability and validity among primary school teachers in Vietnam. Methods: The VFI was translated using a forward-backward method. A cross-sectional study was conducted with 339 primary school teachers. Internal consistency was assessed using Cronbach's alpha, and test-retest reliability was measured with intra-class correlation coefficients (ICC). Construct validity was evaluated using confirmatory factor analysis (CFA), and criterion validity was assessed using receiver operating characteristic (ROC) an..