The sniffing bead system, an olfactory dysfunction screening tool for geriatric subjects: a cross-sectional study

BACKGROUND: This study aimed to develop a simple and one-off olfactory screening test, the sniffing bead system, for general clinical use in older adults. METHODS: In this cross-sectional study, geriatric subjects (aged > 50 years) who underwent neurocognitive and olfactory function tests were included. Overall, 137 subjects were enrolled, and the study was conducted at Chung-Ang University, Seoul, Korea. Olfactory function was measured by obtaining the scores of the sniffing bead system using 2-phenylethyl alcohol, n-butanol, and the YSK olfactory function test. Time taken for each olfactory function test was also measured. RESULTS: The score of the 2-phenylethyl alcohol sniffing bead test was 2.58 ± 1.52, which was significantly associated with the YSK_threshold (2.41 ± 1.79) (p < 0.001, Pearson’s correlation coefficient = 0.429), YSK_identification (8.93 ± 3.25) (p = 0.014, Pearson’s correlation coefficient = 0.208) and YSK_threshold-discrimination-identification (17.46 ± 5.49) (p < 0.001, Pearson’s correlation coefficient = 0.316) test scores. In the normal cognitive function group, YSK_threshold (p < 0.001, Pearson’s correlation coefficient = 0.479), YSK_identification (p = 0.003, Pearson’s correlation coefficient = 0.316), and YSK_threshold-discrimination-identification (p < 0.001, Pearson’s correlation coefficient = 0.429) were significantly correlated with the scores of the 2-phenylethyl alcohol sniffing bead system. In the impaired cognitive function group, the YSK_threshold (p = 0.002, Pearson’s correlation coefficient = 0.415) and YSK_ threshold-discrimination-identification (p = 0.004, Pearson’s correlation coefficient = 0.385) were significantly correlated with the scores of the 2-phenylethyl alcohol sniffing bead system. Time taken for the 2-phenylethyl alcohol sniffing bead system was 5.00 ± 1.51 min, which was significantly lower than that for the YSK_threshold-discrimination-identification (20.43 ± 5.29 min) (p < 0.001). The scores of the 2-phenylethyl alcohol sniffing bead system were significantly correlated with those of the n-butanol sniffing bead system (3.50 ± 1.21) (p < 0.001, Pearson’s correlation coefficient = 0.315). CONCLUSIONS: This sniffing bead system was specifically designed for screening olfactory function in older adults, and it may allow for the rapid and accurate assessment of olfactory dysfunction. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-020-01871-7.