A computer-controlled olfactometer for a self-administered odor identification test

Odor identification tests are widely used for the general screening of olfactory function. However, the administration of odor identification tests is often limited due to a lack of investigators' time. Therefore, we attempted to design a computer-controlled olfactometer to present a self-administered odor identification test. The results produced by means of this olfactometer were evaluated in terms of validity and test-retest reliability. To test the validity, participants' performance in the odor identification test using the olfactometer was compared with their performance in the odor identification test using the validated assessment of the Sniffin' Sticks test. The ten-item odor identification test was performed two times using two different methods: (1) the self-administered test using the computer-controlled olfactometer and (2) the foreign-administered test using the Sniffin' sticks. To examine test-retest reliability, 20 participants were asked to repeat these tests on a different day. Participants reached significantly higher scores on a foreign-administered odor identification test using the Sniffin' sticks than on the olfactometer-based test; however, this effect was driven by two less correctly identified odors in the olfactometer-based test. The significant difference between both methods in the mean scores disappeared after excluding two odors from the analysis. In addition, both methods showed no significant difference in scores obtained during the first and second session, indicating that results were consistent between sessions. In conclusion, our findings demonstrate that the computer-controlled olfactometer designed in this study can be used for a self-administered odor identification test.