Psychometric Properties of the Persian Version of Dizziness Handicap Inventory.

Introduction: The present study was designed to investigate the psychometric properties of the Persian version of the Dizziness Handicap Inventory (P-DHI). In addition, this research was targeted toward assessing the association of P-DHI with Medical Outcome Study 36-Item Short Form Health Survey (SF-36) and Hospital Anxiety and Depression Scale (HADS). The current study also involved a comparison of the scores of patients and healthy participants and implementation of a factor analysis.

Materials And Methods: This cross-sectional study was conducted on 113 patients with dizziness and 30 healthy individuals referring to tertiary centers for otolaryngology and neurology, affiliated to Guilan University of Medical Sciences, Rasht, Iran. The mean age of the patients was 44.5±13.6 years. All patients re-completed the P-DHI after 2 weeks. Internal consistency and reproducibility of the inventory were evaluated using the Cronbach's alpha coefficient, Bland-Altman limits of agreement, and intraclass correlation coefficients. In addition, the relationships of the P-DHI with SF-36 and HADS were evaluated using the Spearman correlation coefficient. An exploratory factor analysis was also run to determine the factor structure of the questionnaire.

Results: The Cronbach's alpha coefficient of P-DHI scale was obtained as 0.86. In addition, the functional, physical, and emotional subscales of this instrument had the Cronbach's alpha coefficients of 0.76, 0.52, and 0.80, respectively. The limits of agreement were 16 points for the total scale, and the range of intraclass correlation coefficients was 0.90-0.96. The P-DHI showed a fair correlation with vertigo severity which assesses functional disability subscale. This scale also demonstrated a moderate correlation with SF-36 and HADS. Factor analysis revealed a 2-factor solution which was different from the factor structure of the original DHI.

Conclusion: As the findings indicated, the P-DHI had good psychometric properties; therefore, it could serve as a useful tool for measuring disability in patients with dizziness and unsteadiness.