Vocal Tract Discomfort Scale: Adaptation, Validity, and Reliability of the Turkish Version

Abstract

Currently, there is no Turkish assessment tool available for the evaluation of vocal tract discomfort. The objective of this study is to cross-cultural adaptation of the Vocal Tract Discomfort Scale (VTDS) to Turkish and assess its validity and reliability. The study was conducted with a total of 214 participants, consisting of 121 individuals with voice disorders and 93 individuals without voice disorders. All participants completed the Voice Handicap Index (VHI), Voice-Related Quality of Life (VRQOL), and VTDS. To conduct a test-retest reliability assessment, the VTDS was administered again to 54 participants within 7-14days. The internal consistency of VTDS was evaluated using Cronbach's alpha coefficient. The Cronbach's alpha coefficient for the scale was calculated at 0.964, while it was 0.922 for the frequency subscale and 0.930 for the severity subscale. It was found that there was a high degree of correlation (rho=0.868, frequency rho=0.847, severity rho=0.875, P<0.001) between the two administrations, indicating the reliability of the test-retest assessment. To assess the criterion validity of the scale, correlations between VTDS total scores and VHI and VRQOL scales were examined. Accordingly, it was found that there was a high degree of correlation between VTDS and VHI (rho=0.631, frequency rho=0.635, severity rho=0.616, P<0.001). It was also observed that there was a high degree of negative correlation between VTDS and VRQOL (rho=-0.701, frequency rho=-0.702, severity rho=-0.692, P<0.001). It was assumed that there would be statistically significant differences in VTDS total scores among the diagnostic groups, and it was found that there was a significant difference between the two groups (U=1095.000, z=-10.110, P<0.001). These findings support the discriminative validity of VTDS. The Turkish version of VTDS is a valid and reliable scale that can assess perceptible symptoms and sensations in the vocal tract in terms of both frequency and severity.