title: Adaptation and validation of the Singing Voice Handicap Index into Polish.
abstract: OBJECTIVE
  To translate and adapt the original Singing Voice Handicap Index (SVHI) for the Polish population and to evaluate the psychometric properties of the Polish SVHI version, such as internal consistency, reliability and construct validity in different groups of dysphonic singers.
  
  
  METHODS
  Prospective case-control study.
  
  
  METHODS
  Patients treated at a single institute.
  
  
  METHODS
  Sixty singers with voice disorders and 57 healthy singers completed the SVHI and the Voice Handicap Index (VHI). Thirty singers completed the SVHI twice within a 2- to 4-week interval.
  
  
  METHODS
  Internal consistency, test-retest reliability, discriminant validity, criterion-related validity RESULTS: A strong Cronbach's alpha coefficient (0.96) indicates that the SVHI items are measuring the same construct. Evaluating the test-retest reliability, the r-Spearman correlation coefficient was r = 0.797 for the total score of SVHI, which shows a good level of reproducibility. There were significant differences between the control group (CG) and patients with benign vocal fold lesions (P < 0.001), CG and singers with muscle tension dysphonia (P < 0.001), CG and coexistence of muscle tension dysphonia and chronic laryngitis (P < 0.001). There was a positive statistically significant correlation between SVHI and VHI (r = 0.753, P = 0.000*).
  
  
  CONCLUSIONS
  The Polish version of SVHI serves as a valid health status instrument, as well as discriminating between singers with voice disorders and singers without voice problems. The SVHI is easy to perform in clinical practice.
authors.affiliation: Department of Otolaryngology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: E M
authors.identifier: http://orcid.org/0000-0002-1940-8060
authors.initials: EM
authors.lastname: Sielska-Badurek
authors.affiliation: Department of Biophysics and Human Physiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Sobol
authors.affiliation: Department of Otolaryngology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Cioch
authors.affiliation: Department of Otolaryngology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: E
authors.initials: E
authors.lastname: Osuch-Wójcikiewicz
authors.affiliation: Department of Otolaryngology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: A M
authors.initials: AM
authors.lastname: Rzepakowska
authors.affiliation: Department of Otolaryngology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Niemczyk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011044:Poland; D011446:Prospective Studies; D011594:Psychometrics; D015203:Reproducibility of Results; D063346:Singing; D014832:Voice Disorders / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult