title: The Psychometric Properties of the Voice Handicap Index in People With Parkinson's Disease.
abstract: BACKGROUND
  Psychosocial impact of dysphonia in people with Parkinson disease (PD) has been described with the Voice Handicap Index (VHI); however, its psychometric properties when applied in this population are not described.
  
  
  OBJECTIVE
  The objective of this study was to examine the psychometric properties of the VHI in people with PD.
  
  
  METHODS
  A cross-sectional study of 151 subjects without cognitive impairment (90 people with PD and 61 controls) was carried out. The VHI was applied along with clinician-based (Mini Mental State Examination, Hoehn and Yahr staging, and Movement Disorder Society-Unified Parkinson's Disease Rating Scale) and patient-based (self-rated voice severity) outcome measures. The psychometric properties of the VHI analyzed were the feasibility, reliability, and construct validity.
  
  
  RESULTS
  The average age of the PD population studied was 67 years; 51% had a primary level of education and 81% were retired. On average, they had disease onset duration of 11 years, a mild disease stage, mild to moderate global motor disability and impairment, and a normal to mild self-rated voice severity. The psychometric attributes of the VHI demonstrated that the questionnaire is feasible (missing data less than 1%), reliable (Cronbach α > 0.9), and valid (71.5% of the total variance is explained by five factors, correlates with voice severity, PD disability, and impairment, and differentiates subjects with PD from subjects without PD).
  
  
  CONCLUSIONS
  The VHI is a reliable and valid tool that can be recommended for the population under study although further work is required to investigate its utility in advanced stages of disease.
authors.affiliation: Department of Speech Therapy, Escola Superior de Saúde de Alcoitão, Estoril, Portugal; Clinical Pharmacological Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal. Electronic address: isabelpeixotoguimaraes@gmail.com.
authors.forename: I
authors.initials: I
authors.lastname: Guimaraes
authors.affiliation: Clinical Pharmacological Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal; Campus Neurológico Sénior, Torres Vedras, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Cardoso
authors.affiliation: Aix-Marseille Université/CNRS, Laboratoire Parole et Language (LPL), Aix-en-Provence, France.
authors.forename: S
authors.initials: S
authors.lastname: Pinto
authors.affiliation: Clinical Pharmacological Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal; Campus Neurológico Sénior, Torres Vedras, Portugal.
authors.forename: J J
authors.initials: JJ
authors.lastname: Ferreira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005240:Feasibility Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D011237:Predictive Value of Tests; D011594:Psychometrics; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014832:Voice Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D014833:Voice Quality
keywords: Parkinson's disease; Voice Handicap Index; psychometrics; self-assessment; voice complaints