Transcultural Adaptation and Validation of the Korean Version of the Vocal Tract Discomfort Scale

Abstract

The present study translated the Vocal Tract Discomfort Scale (VTDS) into Korean (K-VTDS) and evaluated its reliability and validity. This was a prospective study. The VTDS was first translated into Korean and validated. One hundred and fifty-nine patients with voice disorders were divided into three different diagnostic groups (functional, structural, and neurologic voice disorder) and 131 vocally healthy adults were also included. All participants completed the K-VTDS and the Korean version of the Voice Handicap Index (K-VHI) and Korean versions of the Voice-Related Quality of Life (K-VRQOL). The internal consistency of the K-VTDS was analyzed through Cronbach's α coefficient. The VTDS score differences related to the diagnostic groups were assessed with t test and analysis of variance. We assessed the correlation between the K-VTDS, the K-VHI, and the K-VRQOL using Pearson's correlation analysis. High internal consistency and the test-retest reliability of the K-VTDS were found. The voice disorder group had significantly higher K-VTDS scores for the subscales and total scores than those in the healthy group (P < 0.001). The K-VTDS scores for the subscale of frequency and total scores were highest in the functional voice disorder group. We found a significant difference in frequency and total score of the K-VTDS between the functional voice disorder group and the structural voice disorder group (P < 0.05). We observed a strong positive correlation among the scores for the subscales of frequency and severity, and total scores in the K-VTDS. The K-VTDS showed moderate correlation with the K-VHI and the K-VRQOL. The K-VTDS is a reliable and valid instrument for voice assessment for voice disorders in Korean-speaking patients.