Listening-Related fatigue in adults: cross-cultural adaptation and validation of the Italian version of the Vanderbilt Fatigue Scale.

Abstract

Introduction: Individuals with hearing loss frequently encounter augmented listening-related fatigue due to the elevated effort required for auditory processing, which can be evaluated using the Vanderbilt Fatigue Scale for Adults (VFS-A-40). The objective of this study was to cross-culturally adapt the VFS-A-40 into Italian and validate the Italian version of the scale (VFS-A-40-Ita).

Methods: The study employed an observational design, with rigorous cross-cultural adaptation and back-translation procedures. The data were collected from a large sample of native Italian speakers aged 18 years or older without neuropsychological and/or cognitive disorders. The sample was recruited through convenience sampling and included 125 adults with hearing loss (AHL) and 203 adults with normal hearing (ANH). The validation of the VFS-A-40-Ita entailed the assessment of its construct validity (structural validity, known-groups validity, and convergent validity), internal consistency, test-retest reliability, and content validity. Additionally, face validity was assessed by a panel of 10 audiological experts, including individuals with hearing loss.

Results: The results indicated a statistically significant difference in perceived hearing fatigue across different domains for AHL participants. Indeed, AHL tended to rate the cognitive domain as more impaired than the other domains. As for structural validity, the results of the confirmatory factor analysis provided support for a first-order one-dimensional solution comprising four correlated factors, thereby justifying the use of a total fatigue score. The known-groups validity demonstrated statistically significant differences between the AHL and ANH groups for all variables under analysis. The convergent validity was confirmed with a moderate correlation between the total scores on the VFS-A-40-Ita and scores related to the physical and mental symptoms of persistent generic fatigue (r > .39; p < .01). Internal consistency analysis revealed Cronbach's alpha values greater than .96 for the VFS-A-40-Ita total score, indicating high reliability. Test-retest reliability showed robust correlations between baseline and retest scores (p < .01). Content validity was deemed adequate, with almost all items meeting the item-level content validity index cut-off score of .78, as rated relevant or highly relevant by at least 8 out of 10 experts.

Conclusion: the findings of this study provide substantial evidence for the validity of the VFS-A-40-Ita, confirming its relevance, validity, and reliability for the assessment of listening-related fatigue in Italian-speaking adults. The instrument is open access and suitable for use in clinical settings and for future research, providing a valuable subjective outcome measure for initial assessment, follow-up and post-intervention evaluation within bio-psychosocial and evidence-based clinical practice.