**3.3 Overall improvement rate**

Overall, after completing the treatment, 36 patients (50.0%) showed improvement including a clear (14 patients, 19.4%) and partial (22 patients, 30.6%) improvement. In improvement group, the average age was 51.2 years (range, 19 to 76), the average time interval from the onset of hearing loss to the start of AT was 51.06 ± 69.39 days (range, 1 to 330) and the average improvement in PTA was 24.47 ± 14.85 dB (range, 9 to 63) including two cases which the average improvement in PTA was less than 10dB, but PTA was within 25dB.

### **3.4 Gender, age, location of lesion, vertigo, hypertension and diabetes mellitus**

There was no significant difference in the gender distribution between improvement and no improvement groups. Also, no significant difference between groups was observed in regards to the occurrence of vertigo, the location of lesion, presence of hypertension and diabetes mellitus (Table 1).

Seventy-two patient charts were reviewed (40 males, 32 females). The average age of the patients was 49.4 years (range, 8 to 76) and the average time interval from the onset of

Before acupuncture, mean PTA scores of improvement and no improvement groups were 63.92 ± 22.82 dB and 63.78 ± 17.99 dB, respectively and there was no statistical difference between groups (P = 0.977). After AT, mean PTA of improvement and no improvement groups were 39.55 ± 21.77 dB and 62.64 ± 18.23 dB, respectively and a significant difference

hearing loss to the start of AT was 109.1 days (range, 1 to 1460).

**3.2 PTA changes before and after acupuncture treatment** 

\* : Statistically significant difference, P<0.05 using independent-samples T test

Fig. 2. Mean PTA before and after AT between Improvement and No Improvement Groups

Overall, after completing the treatment, 36 patients (50.0%) showed improvement including a clear (14 patients, 19.4%) and partial (22 patients, 30.6%) improvement. In improvement group, the average age was 51.2 years (range, 19 to 76), the average time interval from the onset of hearing loss to the start of AT was 51.06 ± 69.39 days (range, 1 to 330) and the average improvement in PTA was 24.47 ± 14.85 dB (range, 9 to 63) including two cases which the average improvement in PTA was less than 10dB, but PTA was within 25dB.

**3.4 Gender, age, location of lesion, vertigo, hypertension and diabetes mellitus** 

There was no significant difference in the gender distribution between improvement and no improvement groups. Also, no significant difference between groups was observed in regards to the occurrence of vertigo, the location of lesion, presence of hypertension and

between groups was evident (P = 0.000) (Fig. 2).

**3.3 Overall improvement rate** 

diabetes mellitus (Table 1).

**3. Results** 

**3.1 Patient population** 


\* Statistically significant difference, P<0.05 using χ2 test or Fisher's Exact test

Table 1. Relationship of Character of Patients and Improvement of ISSHL

#### **3.5 Time interval from the onset of hearing loss to the start of acupuncture treatment**

The time intervals from the onset of hearing loss to the start of AT for improvement and no improvement groups were 51.06 days (±69.39 SD) and 167.22 days (±265.01 SD), respectively, which differed significantly (P=0.013) (Table 2).


\* Statistically significant difference, P<0.05 using independent-samples T test

Table 2. Differences in the Time Interval from the Onset of Hearing Loss to the Start of Acupuncture Treatment between Improvement and No Improvement Groups

Effects and Prognostic Factors of

variables (Table 5).

**3.7 Important variables for ISSHL improvement** 

1 pure tone at 500Hz (middle-low frequency

3 pure tone at 1000Hz (middle-high frequency

4 pure tone at 250Hz (low frequency range) on

5 pure tone at 2000Hz (high frequency range) on the day of the initial visit

6 time interval from the onset of hearing loss to

\* 1 screened field: presence of diabetes mellitus

**3.8 Prognosis factors for ISSHL improvement** 

western treatment (Eisenberg DM et al., 1998).

Improvement of ISSHL

improvement (Fig. 3).

**4. Discussion** 

range) on the day of the initial visit

range) on the day of the initial visit

the day of the initial visit

the start of acupuncture treatment (categorical)

Table 5. Results of Feature Selection of Important Variables Contributing to the

Acupuncture Treatment for Idiopathic Sudden Sensorineural Hearing Loss 399

In the feature selection analysis to classify the most important variables to the improvement of ISSHL by AT, pure tone at each frequency (250, 500, 1000, 2000 Hz), PTA on the day of the initial visit and time interval (categorical variable) were determined to be important

Rank Field Importance Value

2 pure tone average on the day of the initial visit Important 1.0

7 age Unimportant 0.727 8 presence of vertigo Unimportant 0.217 9 location of lesion (right / left) Unimportant 0.18 10 presence of hypertension Unimportant 0.166 11 Gender Unimportant 0.133

Based on the results of feature selection model, we identified the prognosis factors that affect ISSHL improvement by AT using a decision tree model. In patients who started AT within 2 weeks and over 6 months, the improvement was not affected by PTA on the day of the initial visit. Otherwise, in patients who started treatment 6 weeks - 6 months PTA on the day of the initial visit were found to be important variables to the prognosis for ISSHL improvement. Especially, in patients who started treatment between 2 and 6 weeks, pure tones at 500Hz (middle-low frequency range) were found to be important variables to the prognosis for ISSHL

Acupuncture is one of the most important tools in traditional Chinese Medicine (TCM). There are meridian and acupuncture point theory in TCM, and according this theory TCM doctors usually choose multiple acupuncture points and combine them for treatment. Since early 1970s, people have paid attention to acupuncture as a complementary therapy of

Important 1.0

Important 1.0

Important 1.0

Important 0.993

Important 0.988

To analyze the relationship between ISSHL improvement and the time interval, we divided 72 patients into four groups (within 2 weeks, 2 – 6 weeks, 6 weeks – 6 months and over 6 months groups). In this analysis, 9 of 10 patients (90%) and 15 of 25 patients (60%) showed improvement with the time interval within 2 weeks and 2 - 6 weeks, respectively. Only 10 of 26 patients (38.5%) and 2 of 11 patients (18.2%) showed improvement with the time interval of 6 weeks – 6 months and greater than 6 months, respectively (Table 3).


\* Statistically significant difference, P<0.05 using χ2 test

Table 3. Relationship between the Time Interval and ISSHL Improvement

## **3.6 Severity of hearing loss on the day of initial visit as a prognostic factor**

As mentioned earlier, there was no difference in mean PTA before and after AT between improvement and no improvement groups (Fig. 2).

To evaluate the co-relationship between severity of hearing loss and time interval with improvement, we divided patients with 2 groups; within 6 weeks and over 6 weeks. Within 6 weeks, there was no difference of severity of hearing loss on the day of initial between improvement and no improvement groups (P = 0.145). On the other hand, over 6 weeks, severity of hearing loss on the day of initial in no improvement group was higher than in improvement group. However, there was no statistical significance (P = 0.055) (Table 4).


\* Statistically significant difference, P<0.05 using Mann-Whitney U test

Table 4. Severity of Hearing Loss on the Day of Initial Visit as a Prognostic Factor
