title: Correlation of Iranian Voice Quality of Life Profile (IVQLP) to VHI-30 and VRQOL: Construct Validity Evidence.
abstract: OBJECTIVE
  An important domain in health-related quality of life evaluations is quality of life perceptions due to having a voice disorder. The purpose of the current study was (1) to examine the correlation of the Iranian Voice Quality of Life Profile (IVQLP) with the Voice-Related Quality of Life (VRQOL) and Voice Handicap Index-30 (VHI-30) for establishing the construct convergent validity of the IVQLP, and (2) to examine the correlation between VRQOL and VHI-30.
  
  
  METHODS
  Study sample consisted of 150 patients, 91 male and 59 female, diagnosed with muscle tension dysphonia, benign organic disorders such as polyps and nodules, and unilateral vocal fold paralysis. In total, 150 patients aged 46.53 ± 13.84 years completed the IVQLP and Persian versions of the VHI and VRQOL.
  
  
  RESULTS
  The results showed that Spearman rank-order correlation coefficient between the results of the VHI and IVQLP questionnaires was 0.90 (P < 0.001). The correlation coefficient between VRQOL and IVQLP was -0.88. (P < 0.001) The Spearman correlation between VHI and VRQOL was -0.94. (P < 0.001) CONCLUSIONS: The current study showed that the IVQLP has good construct validity, and it can evaluate quality of life in Iranian dysphonic patients based on their culture. Also, the VHI-30 and VRQOL correlation was very high.
authors.affiliation: Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Electronic address: dehqan@usa.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Dehqan
authors.affiliation: Department of Communication Sciences and Disorders, Bowling Green State University, Bowling Green, Ohio.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Scherer
authors.affiliation: Department of Speech Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Fariba
authors.initials: F
authors.lastname: Yadegari
mesh_terms: D000328:Adult; D055154:Dysphonia / Q000523:psychology*; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
keywords: IVQLP; Iranian population; Quality of life; VHI; Voice disorders