Translation, cross-cultural adaptation and validation of the Bulgarian version of the Dizziness Handicap Inventory

The aim of the present study was the translation, cross-cultural adaptation and validation of the Dizziness Handicap Inventory in Bulgarian language (DHI-BG).

Ninety-seven vestibular patients (19 men and 78 women, mean age 45.08 ± 13.85 years) took part in the investigation. All participants were asked to fill in the DHI-BG. Internal consistency was estimated using Cronbach’s alpha and item-total correlation, reproducibility by calculating Bland–Altman’s limits of agreement and intraclass correlation coefficients (ICCs). Associations were estimated by Spearman’s correlation coefficients.

The Cronbach’s alpha for the total score, functional, physical and emotional subscales of DHI-BG were 0.88, 0.75, 0.72 and 0.81. The floor and ceiling effects of the DHI-BG total scale were evaluated with respect to the limits of agreement which were ±9.4–14.53 points. Intraclass correlation coefficients (ICCs) for all scale and subscales were higher than the recommended value of 0.75 and determined good test–retest reliability. The range of items correlation for DHI-BG was from 0.27 (item 12) to 0.72 (item 3). No significant differences were observed in the Cronbach’s alpha coefficients between the DHI-BG and the original version, the German and Italian versions of the questionnaire. The most significant difference was observed in comparison with the German version of DHI. Construct validity presented a moderate correlation between Romberg coefficients and DHI-BG scores and strong correlation between all scores of DHI and the self-perceived disability. The results suggest that DHI-BG scores show a good discriminative validity between groups with different levels of self-assessed disability.

The Bulgarian version of the DHI is a reliable and valid tool in assessing the impact of dizziness on the quality of life in Bulgarian vestibular patients.