Assessment of odor identification function in Asia using a modified “Sniffin’ Stick” odor identification test

Odor familiarity is an important factor for odor identification but varies profoundly in different areas. The “Sniffin’ Stick” odor identification test originates from Europe. Modification should be made before it can be used to assess olfactory function in Asia. Replacement of some odorants with more familiar ones is a direct method of modification. The purpose of this study was to establish a modified version of the “Sniffin’ Stick” odor identification test. Five odors of the original odor identification test were changed to become the Veterans-General-Hospital (VGH) version “Sniffin’ Stick” odor identification test. The identifiability, intensity and hedonic tone of the odors were characterized. One hundred and thirty-five subjects with subjectively normal olfaction were enrolled to test the VGH-version set. Another 37 subjects with subjectively normal olfaction were enrolled to investigate the correlation between the original and VGH-version test. The characteristics of odorants in the VGH-version odor identification test fulfilled the prerequisite of the “Sniffin’ Stick” odor identification test. The age effect on the olfactory function was clearly present in the VGH-version test. The test-retest correlation coefficient was 0.85. The tenth percentile of the VGH-version was 14, which served as an absolute cut-off value of normosmia. The Pearson correlation coefficient of the two sets of “Sniffin’ Stick” odor identification was r = 0.72. The VGH-version of the “Sniffin’ Stick” odor identification test is well characterized and capable of assessment of odor identification in the Asian region.