Development of a Southeast Asian version of the "Sniffin Sticks" odor identification test

The odor identification test is an efficient and rapid way to assess and screen a patient's sense of smell. The original Sniffin' Sticks odor identification test (SST) consisted of 16 smells developed for a European population. However, this identification test can be influenced by cultural differences, such as variations in food culture, ethnicity and language. We propose developing a test that uses odors more familiar and specific to the Association of Southeast Asian Nations (ASEAN) population.

The study involved four stages: (1) A familiarity questionnaire to select odors, (2) Testing of selected odors on healthy participants from different regions, (3) Application of the developed test on healthy subjects and those with smell disorders, and (4) Test-retest reliability assessment. A total of 466 participants aged 16 to 87 years were involved across all stages. The final ASEAN Sniffin' Sticks odor identification test (ASST) was conducted on 106 healthy subjects (HS) and 68 subjects with smell disorders, including 29 with Parkinson's disease (PD) and 39 with sinonasal diseases (Ear, Nose, and Throat [ENT]).

Mean scores of 15.75 ± 0.62 were found in the HS group, 9.07 ± 3.67 in the PD group, and 10.90 ± 4.87 in the ENT group, out of a total possible score of 16. The 10th percentile value (score of 15) in HS aged 17-35 was used as cutoff between normal olfaction from those with a smell disorder. There were significant differences between the HS group and both the PD and ENT groups (p < 0.001), but no significant difference was found between the PD and ENT groups (p = 0.068). The ASST demonstrated high test-retest reliability, with a correlation (r) = 0.92 (p < 0.001).

The ASST provides a reliable tool for evaluating olfactory function and detecting olfactory loss associated with various conditions in the ASEAN region.