Applicability of the Cross-Culturally Modified University of Pennsylvania Smell Identification Test in a Japanese Population

Abstract

Background The University of Pennsylvania Smell Identification Test (UPSIT) is a popular olfactory function test used throughout the world. In Japan, however, it is not widely used because it is written in English and some of the test odorants are unfamiliar to the Japanese population. Recently, a cross-culturally modified UPSIT was developed. This study was designed to determine if the Japanese version of the UPSIT (UPSIT-J) is effective in Japanese populations. Methods We administered the UPSIT-J to 50 normosmic Japanese subjects and 54 Japanese patients with known olfactory dysfunction. Subjects were also administered the Japanese standard olfactory threshold test (T&T olfactometry), the Odor Stick Identification Test for Japanese (OSIT-J) and i.v. olfactometry (the Alinamin test). Test results from the UPSIT-J and subjects’ opinions were compared with the standard Japanese tests of olfactory function. Results Most subjects reported that the UPSIT-J was easy and interesting compared with OSIT-J and easier and more interesting than the T&T olfactometry and Alinamin test. Identification rates for nine of the UPSIT-J odorants were found to be < 80% for normal subjects. UPSIT-J scores correlated with subjects’ self-reported levels of olfactory function (r s = 0.85), OSIT-J score (r s = 0.86), recognition threshold of the T&T olfactometry (r s = 0.80), and Alinamin test results (r s = 0.38 for latency; r s = 0.52 for duration time). Conclusion Although a cultural bias was detected for some test odorants, this study indicates that the UPSIT-J is effective for use in the clinic to assess olfactory function in the Japanese population.