Prätestung des deutschen Vocal Fatigue Index (VFI-D) – transkulturelle Übersetzung und Kreuzvalidierung

Abstract

In clinical routine, vocal fatigue is acommon symptom in patients with dysphonia. The aim of this study was to conduct atranscultural translation of the Vocal Fatigue Index (VFI), astandardized subjective questionnaire. Furthermore, pretesting and prevalidation were performed in 20subjects, with comparison to the Voice Handicap Index (VHI‑9i) and the Vocal Tract Discomfort Scale (VTD). The translation, content review, and pretest of the German Vocal Fatigue Index (VFI-D) was divided into four sections: 1.transcultural translation, 2.expert voting on comprehensibility, 3.test of comprehensibility through cognitive interviews in 15participants, 4.pretest of the VFI‑D with cross validation compared to VHI‑9i and VTD in 20subjects. This process corresponds to current standards for transcultural translation and adaptation of questionnaires. According to expert voting and cognitive testing, the VFI‑D is correct and comprehensible (intercoder reliability κ = 0.66). The factor analysis revealed three distinguishable parts: VFI‑D part1 correlates strongly with VHI‑9i and VTD, VFI‑D part2 with VTD only (rho ≈ 0.800 each), and VFI‑D part3 correlates only weakly with VHI‑9i and VTD (rho ≈ 0.585). Thus, convergence and divergence validity are proven. The first German version of the VFI‑D might be abase for further research on symptoms, causes, and treatment options in vocal fatigue. Particularly patients in voice-intensive professions may benefit.