Reliability of clinical measures used to assess patients with peripheral vestibular disorders.

PURPOSE: The purposes of this research were to (1) determine test-retest reliability of clinical measures of self reported disability and subjective complaints, gait, and fall risk; and (2) establish normal variability for each of these measures based on test-retest variability in people with peripheral vestibular disorders.
METHODS: Sixteen patients with confirmed peripheral vestibular disorders performed 2 trials of each of the measures within a single physical therapy session. The measures included rating of disability, percent of day affected by dizziness, head movement induced dizziness, preferred gait speed, gait deviations, and Dynamic Gait Index. In order to assess test-retest reliability of the measures intraclass correlation coefficients (ICC) were calculated.
RESULTS: All measurement tools demonstrated excellent reliability (ICC 3,1 = 0.86 - 1.00) except for head movement induced dizziness (ICC 3,1 = 0.48). For each measure we report normal variability as tested within a single session. DISCUSSION: Clinical measures commonly used in the assessment of vestibular patients were found to have excellent test-retest reliability, except for the subjective measure of head movement-induced dizziness.
CONCLUSION: Incorporation of valid and reliable assessments in clinical practice is critical in order to demonstrate the effectiveness of therapeutic intervention.