Internal consistency and factor analysis of the Dutch version of the Dizziness Handicap Inventory

The Dutch (Belgium) translation of the Dizziness Handicap Inventory (DHI) has proven to be as consistent as the original version. In addition to the three original subscales, factor analysis revealed a fourth component scoring self-perceived effects of insufficient functioning of the vestibulo-ocular reflex (VOR). Focus should be on the DHI total score in order to compare future results with the existing literature.

To conduct a factor analysis and to determine its internal consistency.

Charts of 214 outpatients, referred with dizziness or imbalance of vestibular and non-vestibular origin, were reviewed.

The Cronbach's alpha coefficients for internal consistency were high for the total scale and good for the subscales. Corrected item-total correlations ranged from 0.71 for 'restricted travelling' to 0.29 for 'difficulties reading', when items were correlated with their respective subtotals, and ranged from 0.69 (restricted participation in social activities) to 0.33 (stressed relationships), when correlated with the total score. A principal component analysis with orthogonal rotation was conducted, suggesting a four-factor solution. Two factors were related to vestibular handicap, referring to the original functional and emotional subcategories. The remaining two factors related to vestibular disability, documenting motion sensitivity (original physical subscale) and insufficient VOR functioning.