4 DISCUSSION
Based on the SSOI test, the CMOI test proposed in this study
significantly improved the score of the olfactory test and the correct
recognition rate of odors by using the distra-ctors and odors more
familiar to Chinese people. It is an effective tool for evaluating the
olfactory function of Chinese people.
From the odor familiarity survey, we found that, out of the 64 odor
descriptors in S-SOI test, the familiarity scores of 31 odor descriptors
were <75 points; nearly half of the odors in SSOI test were
unfamiliar to the volunteers. In the olfactory test, it is likely that
although the subjects perceived the odors, they found it difficult to
make a correct choice because they were unfamiliar with the odors or
distractors.
After adjusting the 23 distractors of the SSOI test according to the
odor familiarity survey results, the scores of the olfactory
identification test of healthy volunteers were si-gnificantly improved.
Taking the odor ”cinnamon” as an example, in the SSOI test, only 59% of
the volunteers could correctly identify the odor ”cinnamon”. However,
after ch-anging the distractors, the correct recognition rate of the
odor ”cinnamon” reached 88%. This may be because volunteers were more
familiar with the smell of some new distrac-tors and could choose the
correct answer through exclusion. However, the correct recog-nition
rates of some odors were still low, such as apple, leather, and
pineapple, whose c-orrect recognition rates were 20%, 57%, and 60%,
respectively; many volunteers could not recognize them correctly. This
may be because volunteers were unfamiliar with some odors; even if the
distractors were modified, the recognition rate of the odor “leather”
w-as only improved from 53% to 57%. It may also be because the odor
was familiar, but the name was inaccurate. Take the odor ”apple” as an
example, there are many varieties of a-pples in the world, and the smell
is not exactly the same. The odor ”apple” does not spec-ify the specific
apple variety, and the apple aroma is relatively light, which can be
easily ignored. Therefore, it was difficult for volunteers to make the
correct choice in the test. If the names of both odors and distractors
are inaccurate, the interference of volunteers may be more serious. The
last reason is that the similarity between odors and distractors was
high, and the difference was insignificant. Take the odor ”apple” as an
example again; the distractors of the odor were melon, peach, and
orange. In the identification test, most vol-unteers could only smell
fruit flavour, and these four options all had fruit flavour, increa-sing
the difficulty of accurate identification. To further improve the score
of the olfactory identification test and enable it to have the ability
to test unpleasant odors, through litera-ture search,
tetrahydrothiophene, 2-methylpyrazine, and trimethylindole were selected
to simulate natural gas, burnt smell, and Fecal odor respectively, and
replace three odors: a-pple, leather, and pineapple. After randomly
assigning distractors, the CMOI test was co-mposed of 16 odors: 3 tested
for the third time, and the other 13 unchanged odors.
The CMOI test scores of volunteers were significantly higher than that
of the MDOI test scores and SSOI test scores, which reduced the
occurrence of wrong choices due to t-heir unfamiliarity with some odors
to avoid some subjects being misdiagnosed with olfa-ctory disorder due
to the error of the olfactory test. Moreover, after adjusting the SSOI
te-st, the score of the olfactory identification test was improved so
that the degree of olfact-ory dysfunction can be diagnosed more
accurately when testing patients with poor olfact-ion. Therefore, the
CMOI test focuses on detecting the severity of patients’ olfactory
dys-function and makes it easier to identify patients who are not
sensitive to unpleasant odor-s. It is more suitable for clinical
diagnosis of olfactory disorder and evaluation of treatm-ent effect.
Also, with the overall improvement of the CMOI test score, the olfactory
det-ection ability of people who are too sensitive to smell may decline.
At present, patients with olfactory disorders mostly use pleasant odor
reagents in ol-factory training but rarely use unpleasant odor reagents
with important warning functions, such as natural gas odorant and
simulated burnt odor reagents used in the experiment, w-hich may lead to
poor recovery effect of patients’ olfactory ability to this kind of
odor. In this experiment, the unpleasant smell with a warning function
was introduced into the ol-factory test, which could better detect the
recovery degree of patients’ perception of this kind of smell; this was
of great significance to evaluate the effect of olfactory treatment.
It is hoped to screen patients who cannot correctly identify natural
gas, burnt smell, and Fecal odor for the next treatment to
reduce
patients’ risk in natural gas leakage, fire, and other dangerous events.