Condition of Vocal Production-Teacher questionnaire: comparison of responses on Likert scale and visual analog scale.

PURPOSE To compare the responses related to vocal symptoms in two versions of the Vocal Production Condition - Teacher (CPV-T) questionnaire, with responses on a Likert scale and a Visual Analog Scale (VAS), in order to evaluate which is the best measurement method. METHODS A cross-sectional observational study was conducted with teachers with voice disorders during the period from July 2011 to July 2012. All teachers answered the CPV-T in two versions: with answers on a 4-point Likert scale and on a 50-mm VAS. The answers related to vocal symptoms dimension were analyzed. RESULTS Most of the symptoms showed good (hoarseness, high-pitched voice, unstable voice, weak voice, effort when speaking, throat clearing, burning throat, and pain when speaking) or regular concordance (loss of voice, failing voice, low-pitched voice, vocal fatigue, dry throat, lump in the throat, secretion in the throat, pain when swallowing, difficulty swallowing, and dry cough). CONCLUSION The CPV-T questionnaire with answers on Likert scale proved to be more suitable than the VAS owing to the ease of understanding and interpretation, in addition to facilitating the input of answers for the researcher. Therefore, the Likert scale was chosen for the CPV-T, considering it to be validated as the method to measure the answers. The dimension of vocal aspects evaluated in the present study, the Voice Disorder Screening Index (ITDV), can be used in epidemiological studies to estimate the prevalence of vocal symptoms and in the Speech-Language Pathology and Audiology clinic routine or in monitoring teachers throughout their careers.