Screening index for voice disorder (SIVD): development and validation.

PURPOSE: To develop and validate a score that can serve as a screening index for voice disorders in teachers. METHODS: The subjects of this study were 252 female teachers, with and without voice disorders (WVD and WOVD) from the public school system of São Paulo, Brazil. All subjects underwent medical and vocal evaluations and completed a questionnaire about experienced vocal symptoms. They were then randomly divided into samples A and B. Sample A was used to develop and sample B to validate a screening index for voice disorder (SIVD). The development was done using a factorial analysis, and a cutoff point to predict the risk of having a voice disorder was defined using a receiver operating characteristic curve. The validation was done by calculating sensitivity and specificity values for the cutoff, comparing mean scores of subjects WVD and WOVD, calculating correlation between SIVD and Voice Handicap Index (VHI), and the association between the risk and presence of voice disorder. RESULTS: The SIVD comprised 12 symptoms and each accounts for 1 point on the scale. The cutoff to identify risk of voice disorder is five symptoms. Analyzing sample B, it was found that SIVD has good internal consistency (α=.82) and sensitivity (94%), a strong correlation to VHI, significant association between risk of having and actual presence of voice disorder, and people WVD had higher mean SIVD. CONCLUSION: The SIVD proved to be a reliable valid tool for the identification of voice disorders in teachers, especially for use in screenings, acting as an instrument of epidemiologic vigilance.