Epidemiology and Comorbidities of Vestibular Disorders: Preliminary Findings of the AVOCADO Study.

INTRODUCTION: Studies on incidence and prevalence of vestibular disorders tend to focus on small pockets of patients recruited from specialized clinics and often exclude measures of vestibular function. The objectives of the study were to characterize patients with common vestibular disorders, estimate the prevalence of common vestibular disorders, and ascertain whether patients with vestibular disorders experience increased risks of falls and morbidity. MATERIALS AND METHODS: This retrospective cohort study includes both inpatient and outpatient routine clinical care data culled from a nationally representative, population-based sample. Patients were included if their record in the TriNetX Diamond Cohort comprised at least one vestibular function test or vestibular diagnosis. The main outcome measures were diagnosis with a vestibular disorder, a fall, or a common medical comorbidity (e.g., diabetes, cerebrovascular disease). RESULTS: The cohort includes n = 4,575,724 patients, of which 55% (n = 2,497,136) had a minimum of one vestibular diagnosis. Patients with vestibular diagnoses were 61.3 ± 16.6 years old (mean ± standard deviation), 67% women, 28% White race (69% unknown race), and 30% of non-Hispanic or Latino ethnicity (66% unknown ethnicity). The prevalence of vestibular disorders was estimated at 2.98% (95% confidence interval [CI]: 2.98-2.98%). Patients with vestibular diagnoses experienced a significantly greater odds of falls (odds ratio [OR] = 1.04; 95% CI: 1.02-1.05), cerebrovascular disease (OR = 1.42; 95% CI: 1.40-1.43), ischemic heart disease (OR = 1.17; 95% CI: 1.16-1.19), and diabetes (OR = 1.14; 95% CI: 1.13-1.15), among others. DISCUSSION: Vestibular disorders affect an estimated 3% of the U.S. population, after weighting. Patients with these disorders are at greater risk for many common, consequential medical conditions.

The minimal clinically important difference for gait speed in significant unilateral vestibular hypofunction after vestibular rehabilitation.

Gait speed is a valid measure of both physical function and vestibular health. Vestibular rehabilitation is useful to improve gait speed for patients with vestibular hypofunction, yet there is little data to indicate how changes in gait speed reflect changes in patient-reported health outcomes. We determined the minimal clinically important difference in the gait speed of patients with unilateral vestibular hypofunction, mostly due to deafferentation surgery, as anchored to the Dizziness Handicap Index and the Activities Balance Confidence scale, validated using regression analysis, change difference, receiver-operator characteristic curve, and average change methods. After six weeks of vestibular rehabilitation, a change in gait speed from 0.20 to 0.34 m/s with 95% confidence was required for the patients to perceive a significant reduction in perception of dizziness and improved balance confidence.