Correlation between Olfactory Threshold Test, Olfactory Identification Test and Subjective Symptoms

Choi, Hyo Geun; Lee, Hyung Jong; Shin, Hyun Woo; Lee, Jin Mee; Lee, Chul Hee; Mo, Ji Hun; Kim, Jeong Whun

Abstract

BACKGROUND AND OBJECTIVES: Psychophysical tests such as 16-item Korean Version of Sniffin' Sticks test (KVSS) identification test and Butanol Threshold Test (BTT) are relatively objective tests, but such tests cannot completely explain olfactory complaints. Furthermore, the correlation between KVSS and BTT has not been validated in Korea. We evaluated subjective olfactory symptoms of patients by a questionnaire and the correlation between two tests and the symptom questionnaire.
SUBJECTS AND METHOD
A total of 789 patients who visited olfactory clinic of Seoul National University Bundang Hospital from April 2004 through July 2007 were included in this study. BTT and KVSS identification tests were performed and all the patients filled out an olfactory questionnaire. The questionnaire was composed of 4 parts: general olfaction, general taste, odorspecific olfaction and quality of life. Patients were categorized into 4 groups according to KVSS identification score. KVSS identification scores 0 to 3 represent anosmia, 4 to 7 severe hyposmia, 8 to 12 mild to moderate hyposmia and 13 to 16 normosmia. We analyzed the differences in the subjective symptom questionnaire scores of 4 groups.
RESULTS
KVSS and BTT showed a significant correlation (R=.646, p<.001). Each part of the questionnaire also showed significant correlation to KVSS or BTT. The mean scores of subjective symptoms were 2.69 for anosmia, 3.04 for severe hyposmia, 3.84 for mild to moderate hyposmia and 4.02 for normal and the difference was significant.
CONCLUSION
BTT and KVSS identification test scores and subjective symptoms exhibited significant correlations between each other and the odor-specific olfaction part of the questionnaire showed the greatest correlation to olfactory function tests.