Subjective versus objective tests of dizziness and vestibular function in epidemiologic screening research.

Background Many epidemiologic studies of vestibular disorders are based on responses to questionnaires which have not been tested against objective tests of the vestibular system. Objective The goal was to determine if the dizziness and balance questions used in the National Health Interview Survey (NHIS) are valid and predict performance on objective tests of the vestibular system (VNG). Methods Data from 367 participants recruited from the community, aged 21.4 to 87.6 years, were collected in the Otolaryngology department at a tertiary care center. They were asked the eight NHIS questions twice, at least 30 minutes apart and were tested on VNG. Results Question responses changed from Test 1 to Test 2 and differed between males and females. "Yes" responses did not predict abnormal VNG responses, for the total group and when the group was categorized into younger ( 60 years) subjects. The sensitivity and specificity of all questions was low. Conclusion The NHIS questions provide some information about what people recall of their experiences, but they may not provide insight into the diagnostic prevalence of vestibular and balance disorders because the sensitivity and specificity are too low. Questionnaire-based epidemiologic studies should be interpreted with caution.