Psychometric Properties of the Persian Dizziness Handicap Inventory - Screening Version.

OBJECTIVES: The Dizziness Handicap Inventory (DHI) is the most popular and widely used questionnaire in evaluating patients with vertigo. This questionnaire has a screening version with a high correlation with DHI. This study aimed to assess the psychometric properties of the Persian DHI - Screening version (DHI-S).

METHODS: This cross-sectional and methodological study was conducted on 300 patients at the central vestibular clinic in Mashhad, Iran, from 2020 to 2021. First, the DHI-S was translated into Persian using the backward-forward translation method. Subsequently, the following types of validity and reliability were examined: content validity based on content validity index and content validity ratio, face validity based on impact score, construct validity based on confirmatory factor analysis, internal consistency based on Cronbach's α and Ω, and test-retest stability based on intraclass correlation coefficient and smallest detectable change.

RESULTS: The DHI-S had high content and face validity. Score 8 was selected for the cutoff point between patients and the normal group with a sensitivity of 63.67% and specificity of 96.08%. The construct validity indicated that the questionnaire is one-dimensional. The Cronbach's α and Ω for internal consistency were 0.855 and 0.851, respectively. The intraclass correlation coefficient was 0.981 and the smallest detectable change was 5.521.

CONCLUSIONS: The DHI-S in the Persian language has high and acceptable psychometric properties. This questionnaire can be used in research and clinical settings.