Development of a smell identification test using a novel stick-type odor presentation kit.

The odor identification is strongly influenced by the social and cultural factors; therefore, the odorants used in a smell identification test should be familiar to the test population. In addition, the device used in the test is desired to be simply handled and retain odor quality over time. We developed a novel stick-type odor presentation kit that consists of microcapsules of odorant incorporated into stable cream and the smell identification test using it. Thirteen odorants were selected to be familiar to the test population. In the test, we used two identification methods: one was a modified forced-choice paradigm with "detectable but not recognizable" and "no smell detected" added as choices and the other was a two-step identification paradigm where the participant first selected one of eight odor categories and then chose the specific odor name from the selected category. We verified the performance of the odor stick and the test by stability, using a test-retest paradigm, comparing this test with another smell test, and testing Japanese people from a range of age groups. We conclude that this kit is a useful odor presentation device, and the test using it works effectively as a smell identification test.