(I)INFVo scale for perceptive evaluation of substitutional voices – validation of the Polish version

Abstract

<br><b<Aim:</b> The aim of this study was to evaluate the relevance and reliability of the (I)INFVo scale – a clinical tool for the perceptual assessment of substitutional voice in patients after total laryngectomy. The process involved translating the scale into Polish and verifying the relevance and reliability of the tool in 33 native Polish-speaking patients using tracheo-esophageal or esophageal substitutional voice.</br> <br><b>Methods:</b> Voice recordings were rated using the perceptual-auditory (I)INFVo scale by two experts with 10 years of experience in phoniatrics and speech therapy and a clinical speech therapy graduate. One of the specialists listened to and assessed the voice recordings twice at a one-week interval. Objective measures – speech rate, diadochokinesis (DDK), and maximum phonation time (MPT) were calculated from the aforementioned recordings. The results of the Polish version of Voice Handicap Index (VHI-POL) self-assessment questionnaire including three subscales (functional, physical, and emotional) as obtained from the medical records of the study subjects were also used in the analysis. All values obtained in the study were submitted to correlation analysis.</br> <br><b>Results:</b> Very strong statistical relationships were obtained for inter- and intra-rater reliability. A statistically significant correlation was found between the parameters of the (I)INFVo scale and the objective measures (speech rate, DDK, MPT), the total VHI-POL scores, and the scores within the physical and functional subscales of the VHI-POL questionnaire, confirming the reliability of ratings provided by the experts using the validated scale.</br> <br><b<Conclusion:</b> The perceptual (I)INFVo scale appears to be a reliable and adequate tool for the diagnostics of patients using tracheo-esophageal and esophageal substitutional voice after total laryngectomy.</br>