title: Adaptation and Validation of the Voice Handicap Index (VHI)-30 into Serbian.
abstract: OBJECTIVE
  To evaluate the internal consistency, test-retest reliability, and clinical validity of the Serbian version of the self-administered Voice Handicap Index (VHI)-30.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  The English version of VHI-30 was translated into Serbian and then back-translated into English. The Serbian VHI-30 was administered to 91 patients divided into four groups according to voice pathology: structural, inflammatory, neurologic, and functional groups. The control group included 90 subjects with no voice problems. The internal consistency (Cronbach's alpha coefficient α), test-retest reliability (interclass correlation coefficient) of VHI-30, comparison of patient's and control's VHI-30 scores (Mann-Whitney U test; Kruskal-Wallis test), and correlation with overall severity of dysphonia (Spearman correlation coefficient, ρ) were calculated.
  
  
  RESULTS
  In the patient group, we observed excellent internal consistency for the Serbian VHI-30 (α = 0.95) and good internal consistency for all VHI-30 subscales: physical (α = 0.88), functional (α = 0.88), and emotional (α = 0.88). The interclass correlation coefficient indicated strong test-retest reliability for patients (0.99) and controls (0.84). The mean scores of all 30 items in dysphonic participants were significantly higher than in controls (P < 0.001). Good correlation was obtained between the total scores of VHI-30 and patients' self-perceived overall severity of dysphonia (ρ = 0.748, P < 0.001). Within the patient group, the female participants displayed significantly higher VHI-30 scores than male participants (Mann-Whitney U test, P < 0.001). The VHI-30 scores showed strong correlation within different patient groups and controls (Spearman correlation coefficient: structural, 0.942; inflammatory, 0.756; neurologic, 0.888; functional, 0.982; controls, 0.882).
  
  
  CONCLUSIONS
  The Serbian VHI-30 is a useful and valuable tool for the evaluation of patients with vocal disorders and for making subsequent clinical decisions.
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia. Electronic address: j.sotirovic@gmail.com.
authors.forename: Jelena
authors.initials: J
authors.lastname: Sotirović
authors.affiliation: Institute of Epidemiology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Anita
authors.initials: A
authors.lastname: Grgurević
authors.affiliation: Department of Ear, Nose and Throat Diseases, Faculty of Medicine, University of Novi Sad, Clinical Center of Vojvodina, Novi Sad, Serbia.
authors.forename: Gordana
authors.initials: G
authors.lastname: Mumović
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia.
authors.forename: Uglješa
authors.initials: U
authors.lastname: Grgurević
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia.
authors.forename: Ljubomir
authors.initials: L
authors.lastname: Pavićević
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Perić
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia.
authors.forename: Milan
authors.initials: M
authors.lastname: Erdoglija
authors.affiliation: Clinic for Otorhinolaryngology, Military Medical Academy, Belgrade, Serbia.
authors.forename: Milanko
authors.initials: M
authors.lastname: Milojević
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D004644:Emotions; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011788:Quality of Life; D015203:Reproducibility of Results; D012649:Self Concept; D055771:Serbia; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014175:Translating; D014832:Voice Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D014833:Voice Quality
keywords: Quality of life; Questionnaire; Serbian version; Validity; Voice Handicap Index