Translation, Cross-Cultural Validation of the Voice Handicap Index (VHI-30) in Slovak Language

Purpose. The objective of the study is to verify the psychometric properties of Voice Handicap Index (VHI-30) in Slovak language. Methods. Original VHI-30 has been translated into the Slovak language. Fifty-two dysphonic individuals and 104 individuals of the control group without voice disorders were included in the study. Item to total correlation, internal consistency (Cronbach's alpha coefficient alpha and split-half coefficient), test-retest reliability (correlation coefficient), and validity of VHI 30 (Kruskal-Wallis test) were analyzed. Results. Item analysis proved that questionnaire items have a good to excellent correlation to the total score (0.42-0.87, P < 0.05). Good internal consistency was proved by calculating Cronbach's alpha coefficient (0.88, P < 0.05) and split-half correlation for the Total score in VHI (0.997, P < 0.05). Test-retest reliability was found to be strong (0.86, P < 0.05). Validity results of Slovak VHI suggests that total mean scores of control group were significantly lower than total mean scores of dysphonic groups (structural, neurogenic, inflammatory, functional, and non-specified). Total mean scores indicated no statistically significant difference between dysphonic groups (P < 0.05). The cut-off value of 21 points was determined by Receiver Operating Characteristics (ROC) analysis. Conclusion. The results of the study proved that the Slovak VHI-30 is a reliable and valid tool. It is useful for assessing disadvantage related to voice disorders from the patient's perspective.