Development, validity, and reliability of the Parkinson's voice and speech handicap index (PaVSHI).

OBJECTIVE: The primary aim of this study was to develop a valid and reliable scale for assessing the physical, functional, and emotional impact of voice and speech problems in People with Parkinson’s disease (PwPD). Study Design: The study was conducted in two phases using an exploratory sequential mixed-methods approach. METHODS: In the first phase, semi-structured interviews were conducted with 11 PwPD experiencing voice and speech complaints. Data were analyzed to identify codes, categories, and themes (physical, functional, emotional) to generate scale items. In the second phase, the scale’s validity (content, construct, criterion, known-groups) and reliability (test–retest, internal consistency) were assessed. Expert review resulted in a preliminary 55-item scale, which was administered to 77 PwPD and 113 age- and gender-matched healthy controls. RESULTS: Factor analysis determined construct validity, and the final scale was refined to a 19-item, two-factor structure (Physical-Functional and Social-Emotional). Knowngroups validity revealed significant differences between the study and control groups. Criterion validity demonstrated a positive correlation with the Voice Handicap Index and a strong negative correlation with the Communicative Effectiveness Survey- Revised. Reliability analysis yielded a Cronbach’s alpha of 0.971. CONCLUSIONS: These findings indicate that the Parkinson’s Voice and Speech Handicap Index is a valid and reliable instrument for assessing the impact of voice and speech problems in PwPD. It is recommended that this tool be used in both clinical and research settings to evaluate the impact of speech and voice problems on daily life and to examine the effectiveness of intervention methods.