Cross-Cultural Adaptation, Validation, and Cutoff Values of the Chilean Version of the Voice Symptom Scale: VoiSS.

Objective: To evaluate psychometric properties of the Voice Symptom Scale (VoiSS) - Chilean Spanish version.

Study Design: Cross-sectional, nonrandomized, prospective study with controls.

Methods: The validation of the Chilean Spanish VoiSS version met the criteria of the Scientific Advisory Committee of the Medical Outcomes Trust: Cultural and linguistic adaptation, by translation into Chilean Spanish and back-translation. Validity, employed external criteria (excellent, very good, fair, and poor). Reliability was made by test-retest and responsiveness to treatment, the initial voice and after vocal treatment of 12 dysphonic patients were analyzed, by GRBAS. The Chilean Spanish adapted VoiSS protocol, Escala de Síntomas Vocales (ESV-CL), was applied to 205 subjects, 89 with dysphonia and 116 of them vocally healthy. A cutoff value for the total score was determined by the efficiency characteristics.

Results: The ESV-CL demonstrates high validity, reliability, and responsiveness. A cutoff score of 35.5 was determined by using the high sensitivity (90%) and specificity (75%) found in subjects with dysphonia compared to vocally healthy subjects.

Conclusions: The results of the Chilean version of VoiSS, renamed the ESV-CL, revealed it to be culturally equivalent to the original version, and to be a valid, reliable, and responsive instrument for voice symptoms in the Chilean population. Chilean speech-language pathologists can benefit from this adapted protocol in clinical research and voice management.