Measuring Vocal Fatigability in Teachers: The Vocal Fatigability Scale for Teachers (VFS-T).

OBJECTIVES: This study focuses on the distinction between vocal fatigability and vocal fatigue (VF), highlighting the importance of vocal fatigability when assessing teachers' quality of life. Vocal fatigability is more critical for quality of life than performance or perceived VF because it considers the accumulation and chronicity of fatigue over isolated tasks. The objectives are to develop and validate the Vocal Fatigability Scale for Teachers (VFS-T), to assess teachers' levels of vocal fatigability, and to analyze variations based on personal and occupational traits. The VFS-T construct encompasses items related to vocal sensations and performance, their connection to accumulated demanding vocal activity, descriptions of recovery strategies, necessary rest periods, and the impact of VF on daily activities. STUDY DESIGN: A single cross-sectional study with an ex post facto design was conducted. METHODS: The sample consisted of 184 active teachers with various vocal conditions. They completed the VFS-T questionnaire, provided personal and occupational data, and completed the VHI-10 questionnaire. The data collected were analyzed for item refinement, internal structure, reliability, validity, diagnostic capacity, cutoff values, and group differences. RESULTS: The item refinement and internal structure analysis revealed a scale comprising 17 items grouped into two factors. The VFS-T shows good reliability and validity, with cutoffs at <15 for no fatigability, 15-27 for moderate fatigability, and >28 for high fatigability. Most teachers fall into the moderate fatigability range, with 72% experiencing vocal fatigability. CONCLUSIONS: The VFS-T is a reliable tool for detecting vocal fatigability in teachers. This scale focuses on the construct of vocal fatigability, which is related to chronicity of VF and limitations in daily activities in teachers.

Validity and Reliability of Spanish Version of Two Questionnaires of Vocal Fatigue in Female Teachers.

OBJECTIVES: This study aimed to determine the reliability, validity, and the specificity and sensitivity of the Spanish version of two questionnaires, the Voice Fatigue Index (VFI) and the Voice Fatigue Handicap Questionnaire (VFHQ), in female teachers, analyze the influence of the sociodemographic factors on the questionnaires, and conduct a comparative study of the psychometric characteristics of the two questionnaires on vocal fatigue (VF). MATERIALS AND METHODS: The VFI and VFHQ, Spanish version, was produced following a rigorous forward and backward translation. Seventy-one female teachers were recruited to complete the VFI and VFHQ Spanish version. They also completed Voice Handicap Index-10 in its Spanish version to validate the translation of the VF questionnaires. Finally, they completed a self-elaborated questionnaire to describe the factors that influenced their vocal load and other relevant biological, personal, and occupational data. RESULTS: The two questionnaires showed high indicators of reliability for VFI (factor 1 α = 0.92, factor 2 α = 0.85, and factor 3 α = 0.92) and for VFHQ (α = 0.95). The scores from VFIf1, VFIf2, and VFHQ attained high validity values in Pearson's correlation coefficient when compared to the Voice Handicap Index-10 reference questionnaire. VFIf3 showed low validity values in Pearson's when compared to the others VFI factors (f1, f2), the VFHQ, and the Voice Handicap Index-10 reference questionnaire. CONCLUSIONS: The present study showed good reliability and validity of the VFI and VFHQ in its Spanish version. Thus, it is suggested to use the VFHQ to identify and quantify the VF handicap. To identify individuals who suffer from VF or are at high risk of VF and vocal discomfort, we recommend the application of the VFI. Based on validity results, the VFI does not appear to be a valid tool in the detection of individuals who recuperate their voice after an episode of VF.