Validation of a Voice Outcome Survey for Unilateral Vocal Cord Paralysis

Abstract

Current methods to assess voice outcomes in patients with unilateral vocal cord paralysis (UVCP) are limited by expense, reliability, or lack of a true patient-relevant focus. The purpose of this study was to develop and validate a patient-based, disease-specific instrument, the Voice Outcome Survey (VOS), that is brief, reliable, and sensitive to real clinical change in patients with UVCP. Fifty-six consecutive patients with uncompensated UVCP and without complicating comorbid illness received the VOS, the Medical Outcome Study Short Form 36-Item Health Survey (SF-36), and a voice laboratory analysis before and 6 months after type I thyroplasty. Overall, reliability of the VOS was excellent ( r = 0.87, P< 0.0001). The VOS index was significantly ( P < 0.05) correlated to subscales of the SF-36 including social functioning (SF) ( r = 0.56) and physical role functioning ( r = 0.35), as well as changes in objective voice measures such as phonation time ( r = 0.51) and average intensity ( r = 0.44). The VOS index was the most sensitive measure to clinical change after surgery (standardized response means: VOS, 1.92; phonation time, 0.68; SF, 0.58; physical role functioning, 0.53; intensity, 0.51). The VOS is a brief, valid, reliable, and highly sensitive measure of disease-specific health status in patients with UVCP.