Traditional voice evaluations, including imaging techniques, auditory-perceptual ratings, and acoustic and aerodynamic analyses, fail to assess the global handicap that a patient experiences as a result of a voice disorder. The Voice Handicap Index (VHI) is currently one of the most widely used and psychometrically robust instruments for measuring voice disability. The aim of the study is to translate and validate a Polish version of the VHI. The original English-language version of VHI-30 was translated into Polish. We enrolled 188 subjects-123 patients (91 women and 32 men) with voice disorders and 65 controls (53 women and 12 men) without voice disorders. Results obtained by the patients were significantly higher than those obtained by the controls on the Emotional subscale (U = 519.0; p < 0.001), Functional (U = 829.0; p < 0.001), Physical (U = 331.0; p < 0.001), and the global score (U = 390.0; p < 0.001). There were statistically significant negative correlations between maximum phonation time and global score (rho = -0.31; p < 0.01) as well as all three subscales. Shimmer and Smoothed Amplitude Perturbation Quotient were correlated positively with the global score (rho = 0.22; p < 0.05; rho = 0.25; p < 0.01, respectively) and with all three subscales. There were also statistically significant correlations between VHI scores and auditory perceptual evaluation. In the patient group, there was excellent internal consistency (α = 0.97) and strong test-retest reliability (intraclass correlation = 0.94). The cut-off value equal to 17 points was estimated. The Polish VHI showed excellent internal consistency, good test-retest reproducibility, and clinical validity. It is a useful tool for evaluating the voice disability perceived by a patient.
Keywords: quality of life; questionnaire; reliability; validity; voice handicap index.