Translation and validation of the Voice Handicap Index in Tamil language.

Voice Handicap Index (VHI) is the most commonly used tool to assess the quality of life in voice disordered patients. A validated Tamil language version of VHI is not developed yet. Hence, this study was undertaken to translate and validate the Voice Handicap Index in Tamil language, which can potentially benefit Tamil speaking patients with voice disorders. This was a translation and tool validation study done at a tertiary care teaching hospital using an analytical, follow up design according to WHO guidelines. Dysphonic (Group A) and Normal (Group B) respondents were purposively invited to fill a self administered VHI-Tamil questionnaire. The content validity, response process validity, internal consistency and clinical validity of the questionnaire was calculated using appropriate statistical analysis methods using SPSS version 24.0 software. Out of 117 respondents, 61 respondents were dysphonic (Group A) and 56 respondents were normal (Group B). Overall index for content validation was over 0.84, and response process validation was 1.00 in all domains. Overall internal consistency was excellent, with Cronbach's alpha of 0.993. Excellent test-retest reliability was identified using the Spearman rank correlation coefficient (r = 0.96; p-value < 0.001). For clinical validity, a statistically significant difference between the dysphonic and the normal groups, for the overall VHI-Tamil scores and each of the three domain scores was noted. VHI-Tamil was found to be reliable and valid for assessing the quality of life in patients with voice disorders. It can be recommended for future use among Tamil speaking population.