Reliability and Validity of the Turkish Version of the Voice-Related Quality of Life Measure

Abstract

Objectives: This study aims to test the validity and reliability of the Turkish version of the Voice-Related Quality of Life (V-RQOL) questionnaire.

Study design: This is a nonrandomized, prospective study with control group.

Methods: The questionnaire was administered to 249 individuals-130 with vocal complaint and 119 without-with a mean age of 37.8 ± 12.3 years. The Turkish version of the Voice Handicap Index (VHI) and perceptual voice evaluation measures were also administered at 2-14 days for retest reliability. The instrument was submitted to validity and reliability evaluation.

Results: The V-RQOL measure showed a strong internal consistency and test-retest reliability; the Cronbach's alpha coefficient for the overall V-RQOL was 0.969, the physical functioning domain was 0.949, and the social-emotional domain was 0.940. In the test-retest reliability test, the overall V-RQOL was found to be 0.989. The construct validity of the V-RQOL was determined based on the strength and direction of its relation to the VHI and the perceptual voice evaluation measure. The higher the VHI level, the lower the physical functioning, social-emotional, and overall score levels of the V-RQOL (r = -0.927, r = -0.912, r = -0.944, respectively; P < 0.001). Following the perceptual voice self-assessment, a statistically significant difference was found between the V-RQOL scores of individuals who defined their voices as good, very good, and perfect, and those who defined their voices as bad and very bad (P < 0.001).

Conclusions: The results suggest that the Turkish version of the V-RQOL measure has reliability and validity and may play a crucial role in evaluating Turkish-speaking patients with voice disorders.

Keywords: quality of life; reliability; validity; voice; voice disorders.