Translation, Cross-Cultural Adaptation and Reliability of the German Version of the Dizziness Handicap Inventory

Objective: To translate the Dizziness Handicap Inventory into German (DHI-G) and investigate reliability, assess the association between selected items of the University of California Los Angeles Dizziness Questionnaire and the DHI-G, and compare the scores of patients and healthy participants. Study Design: Cross-sectional design. Setting: Tertiary center for vertigo, dizziness, or balance disorders. Patients: One hundred forty-one patients with vertigo, dizziness, and unsteadiness associated with a vestibular disorder, with a mean age (standard deviation) of 51.5 (13.2) years, and 52 healthy individuals participated. Interventions: Fourteen patients participated in the cognitive debriefing; 127 patients completed the questionnaires once or twice within 1 week. Main Outcome Measures: The DHI-G assesses disability caused by dizziness and unsteadiness; the items of the University of California Los Angeles Dizziness Questionnaire assess dizziness and impact on everyday activities. Internal consistency was estimated using Cronbach alpha, reproducibility by calculating Bland-Altman limits of agreement and intraclass correlation coefficients. Associations were estimated by Spearman correlation coefficients. Results: Patients filled out the DHI-G without problem and found that their self-perceived disabilities were mostly included. Cronbach alpha values for the DHI-G and the functional, physical, and emotional subscales were 0.90, 0.80, 0.71, and 0.82, respectively. The limits of agreement were +/- 12.4 points for the total scale (maximum, 100 points). Intraclass correlation coefficients ranged from 0.90 to 0.95. The DHI-G correlated moderately with the question assessing functional disability (0.56) and fairly with the questions quantifying dizziness (0.43, 0.35). The DHI-G discriminated significantly between healthy participants and patients. Conclusion: The DHI-G demonstrated good reliability and is recommended as a measure of disability in patients with dizziness and unsteadiness.