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Clinical Significance of Results from Olfactory Testing
Author(s) -
Gudziol Volker,
Lötsch Jörn,
Hähner Antje,
Zahnert Thomas,
Hummel Thomas
Publication year - 2006
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/01.mlg.0000234915.51189.cb
Subject(s) - olfactory system , odor , medicine , olfaction , audiology , confidence interval , sensory threshold , statistical significance , logistic regression , psychology , psychiatry , neuroscience , cognitive science
Background: Although widely used in healthy subjects and patients with olfactory loss, the significance of changes of scores from validated olfactory tests is unknown. Aim and Methods: The aim of the present study was to relate the self‐assigned changes of olfactory function in terms of “better,” “unchanged,” and “worse” in patients with smell disorders with the results from olfactory testing by means of a validated test set. Olfactory function of 83 anosmic or hyposmic patients (40 women, 43 men; age 12–84 yr) was tested on two occasions (mean interval 136 days, minimum 7 days, maximum 6.7 yr). Olfactory function was assessed using a validated technique (“Sniffin' Sticks”). This test consists of three subtests, one for odor threshold (T), odor discrimination (D), and odor identification (I), with possible results ranging up to 16 points each. From the sum of the results from the three subtests a composite “TDI” score was obtained. Results: Forty‐four patients indicated an improvement of olfactory function, whereas 39 patients reported no change. No subject reported deterioration of olfactory sensitivity. Subjects assigned to group BETTER had higher TDI scores in the second olfactory tests than subjects assigned to the group UNCHANGED, both in absolute terms and as compared with the first olfactory test (effect “test occasion” by “self‐assessed improvement,” P < .001). There was no significant difference between groups with respect to age and sex ( P = .99 and .84, respectively). Logistic regression showed that more than 60% of the subjects reported an improvement of olfactory sensitivity when the TDI score increased by 5.5 points. Conclusion: We show that there is a statistically significant relation between measured and perceived improvement of olfactory function in patients who first presented with the diagnosis of anosmia or hyposmia. The results indicate that improved olfactory function in patients with olfactory deficiency is perceived as such in everyday life and is quantitatively related to an improvement in the composite TDI score of the “Sniffin' Sticks” olfactory test battery. This is the basis for the application of a specific therapy for olfactory loss because of a possible gain in quality of life for the patients.