Objectives: The 25-item Dizziness Handicap Inventory (DHI) is the most used questionnaire to assess vestibular symptoms. However, the abbreviated 10-item DHI-S is more suitable for daily practice. The objective of this study was to assess validity, reliability, responsiveness, optimal cutoff point for substantial impairment, and minimally important change (MIC) of the DHI-S in general practice.
Study design and setting: We performed a psychometric questionnaire evaluation in general practice. In a prospective cohort study, 415 adults with vestibular symptoms filled out the DHI at baseline, and 1-week, 6-month, and 10-year follow-up. DHI answers were used to calculate DHI-S scores. We assessed validity by criterion validity (Pearson's r) at each measurement. We used longitudinal measurements for test-retest reliability (intraclass correlation coefficient (ICC)) and responsiveness (r). We determined optimal DHI-S cutoff points for substantial impairment (≥30 DHI) and MIC (>11 DHI) with receiver operating characteristic (ROC) curve analyses.
Results: DHI-S demonstrated excellent criterion validity (r = 0.93-0.96), test-retest reliability (ICC = 0.86), and responsiveness (r = 0.89). DHI-S reliably distinguished substantial impairment and identified MIC, with optimal DHI-S cutoff scores of ≥12 points and >5 points, respectively.
Conclusion: The DHI-S is a valid, reliable, and responsive questionnaire that could replace the DHI in general practice.
Keywords: Dizziness; Dizziness Handicap Inventory; General practice; Primary care; Vertigo.
Copyright © 2020 Elsevier Inc. All rights reserved.