[Clinical application of Sniffin' Sticks olfactory psychophysical measurements]

To establish the normal value of Sniffin' Sticks test in Chinese population and to explore it's clinical application in China.

One hundred and five healthy volunteers were choosen from the department of physical examination of Beijing Tongren Hospital between 2007 and 2013. Another 165 patients complained of abnormal olfactory function were obtained from the outpatient clinic of the department of otorhinolaryngology head and neck surgery in the same period and were divided into two groups: 92 in hyposmia and 73 in functional anosmia group. The 270 subjects were divided into 3 subgroups:younger group ( <35 years of age), middle-age group (35-55 years of age) and older group ( > 55 years of age). The olfactory functions were examined with Sniffin' Sticks test and T & T test, respectively. All analyses were performed using SPSS 12.0 software.

For the normal value of Sniffin' Sticks test, TDI score was > 30.12 for younger group, > 27.37 for middle-age group and > 20.43 for older group; the mean TDI score was 32.12 ± 3.95 for healthy group, 17.52 ± 10.37 for hyposmia and 3.56 ± 3.49 for functional anosmia group; the differences in TDI score, olfactory threshold, discrimination threshold and identification threshold between healthy group and olfactory dysfunction group with different ages had statistical significance (Younger group: FTDI = 125.136, P = 0.000; FT = 49.454, P = 0.000;FD = 89.037, P = 0.000; FI = 39.888, P = 0.000; Middle-age group: FTDI = 190.240, P = 0.000; FT = 128.374, P = 0.000;FD = 174.122, P = 0.000;FI = 178.945, P = 0.000;Older group: FTDI = 72.992, P = 0.000; FT = 26.599, P = 0.000; FD = 77.119, P = 0.000; FI = 88.107, P = 0.000, respectively) . The mean T & T value was -1.00 ± 0.98 for healthy group, 2.27 ± 2.01 for hyposmia and 5.89 ± 0.14 for functional anosmia group. T & T score between healthy group and olfactory dysfunction group with different ages had statistical significance (Fyounger = 158.144, P = 0.000; Fmiddle-age = 247.695, P = 0.000; Folder = 70.579, P = 0.000, respectively). TDI score of the Sniffin' Sticks test result was correlated with T & T value (r = -0.927, P < 0.01); T & T threshold was correlated with the olfactory threshold, discrimination threshold and identification threshold of Sniffin' Sticks test (rT = -0.846, P < 0.01, rD = -0.908 P < 0.01, rI = -0.864, P < 0.01, respectively).

Sniffin' Sticks test and T & T olfactometry are able to differentiate normosmia from hyposmia and anosmia with high reliability and consistency in test results.Sniffin' Sticks test can assess subject's olfactory function status more thoroughly and is suitable for application in Chinese population.