Prevalence and impact of bilateral vestibular hypofunction: results from the 2008 US National Health Interview Survey.

IMPORTANCE: Profound bilateral vestibular hypofunction (BVH) causes disabling oscillopsia, chronic disequilibrium, and postural instability, but little is known about its epidemiology and impact.

OBJECTIVE: To assess prevalence and functional impact of BVH in the US adult population.

DESIGN AND SETTING: National cross-sectional survey using a national database and corollary validation study.

PATIENTS: Adult respondents to the 2008 Balance and Dizziness Supplement to the US National Health Interview Survey (N = 21 782).

MAIN OUTCOMES AND MEASURES: Prevalence of BVH, socioeconomic and quality-of-life impact of BVH, and fall risk. Criteria for the survey-based diagnosis of BVH included all of the following: presence of visual blurring with head movement; unsteadiness; difficulty walking in darkness or unsteady surfaces and in a straight path; and symptoms being at least "a big problem" and present for at least 1 year, in the absence of other neurologic conditions or eye pathologic conditions affecting vision.

RESULTS: Adjusted national estimates from this survey indicate the prevalence of BVH in 2008 was 28 per 100 000 US adults (64 046 Americans). Of the participants with BVH, 44% reported changing their driving habits because of their symptoms, 56% reported reduced participation in social activities, and 58% reported difficulties with activities of daily living. Respondents with BVH had a 31-fold increase in the odds of falling in multivariate analyses compared with all respondents, with 25% reporting a recent fall-related injury.

CONCLUSIONS AND RELEVANCE: As estimated by the presence of specific symptoms in a nationally representative survey, BVH has considerable socioeconomic and quality-of-life impacts and significantly increases fall risk. These data support the need for new therapeutic strategies for BVH, including vestibular rehabilitation and implantable vestibular prostheses.