Table 1 Summary of randomized controlled trials of acupuncture for the treatment of tinnitus

Hansen (1982) [16]

17 unilateral tinnitus

46 (9/8)

(A) AT (15 min, 2 times weekly for 3 weeks, n = 17)

(B) Sham AT (Penetrating, non-acupoints, 15 min, 2 times weekly for 3 weeks, n = 17)

Period index (ND with usual tinnitus + 2×ND with usual tinnitus + 3×ND with more pronounced tinnitus)

MD, 2.8 [-3.95, 9.55]

Cross-over

5.3

Denmark

Vilholm (1998) [18]

53 severe tinnitus (both lesion)

53 (35/19)

(A) AT (30 min, total 25 treatment sessions over two months, n = 29)

(B) Sham AT (Penetrating, minimal, non-acupoints, 30 min, total 25 treatments over two months, n = 25)

1) Annoyance (VAS)

1) MD, -5.0 [-21.26, 11.26]

Parallel

9.1

2) Loudness (VAS)

2) MD, -3.40 [-16.66, 9.86]

Denmark

3) Awareness (VAS)

3) MD, -2.00 [-18.50, 14.50]

Jeon (2012) [20]

33 unilateral tinnitus

A: 43.5 (13/4)

(A) AT (10min, 2 times weekly for 5 weeks, n = 17)

(B) Sham AT (Penetrating non acupoints, 10min, 2 times weekly for 5 weeks, n = 16)

1) Tinnitus Handicap Inventory score

1) Post, MD, 0.5 [-14.1, 15.1],NS

Parallel

B: 49.6 (8/8)

2) Symptom I(VAS)

3mo, MD, -2.5 [-15.5,10.5], NS

Korea

A: 37.4

2) Post, MD, -9.5 [-23.9, 4.9], NS

B: 45.6

3mo, MD, -12.5 [-27.0, 2.0], NS

Wang (2010) [21]

50 tinnitus (n.r.)

30-70 (46/4)

(A) AT (25 min, once a week for 6 weeks, total 6 treatments, n = 19)

(C) Sham AT (Penetrating, minimal, non-acupoints, 25 min, once a week for 6 weeks, n = 15)

1) Subjective general evaluation of the treatments

1) A vs. C, MD, -0.02 [-0.12, 0.09], NS

Parallel

n.r.

(B) EA (alternative frequency of 2/100 Hz at 3 s interval, 25 min, once a week for 6 weeks, total 6 treatments, n = 16)

2) Tinnitus occurrence

B vs. C, MD, 0.32 [0.24, 0.39], P < 0.0001

Denmark

3) Tinnitus loudness

2) NS^†

4) Quality reduction of daily life

3) NS^†

5) Effect on the hearing improving

4) NS^†

5) NS^†

Marks (1984) [17]

14 chronic unilateral tinnitus

51 (7/7)

(A) EA with (20 min, once weekly for two weeks, n = 14)

(B) Sham AT (Non-penetrating, non-acupoints, pricking and direct removal, once weekly for two weeks, n = 14)

1) Loudness at a particular time, loudness taking the day as a whole (VAS)

1) NS^†

Cross-over

n.r.

2) Response rate (verbal description of any changes)

2) NS^†

UK

3) Tinnitus matching score

3) NS^†

Okada (2006) [15]

76 tinnitus (n.r.)

57 (29/47)

(A) Scalp AT (manual rotation at 2 Hz, 15 seconds, one time, n = 38)

(B) Sham scalp AT (Penetrating, non-acupoints, manual rotation at 2 Hz, 15 seconds, one time, n = 38)

Subjective symptom relief (VAS)

MD, -1.34 [-2.48, -0.21], P = 0.02 in favor of A

Parallel

n.r.

Brazil

de Azevedo (2007) [12]

38 tinnitus (n.r.)

36-76 (13/25)

(A) Scalp AT (manual rotation at 2 Hz, 15 seconds, one time, n = 19)

(B) Sham scalp AT (Penetrating, non-acupoints, manual rotation at 2 Hz, 15 seconds, one time, n = 19)

Otoacoustic emission amplitude

AT on the left side

Parallel

Parallel

n.r.

- Right side: 3.39 [-1.53, 8.31], NS

Brazil

- Left side: 1.35 [-3.29, 5.99], NS

AT on the right side

- Right side: 3.16[-0.99, 5.99], NS

- Left side: 1.56 [-2.21, 5.33], NS

Tan (2007) [22]

90 nervous tinnitus (n.r.)

18-65 (48/42)

(A) AT (de-qi, 1 session = 20 min, daily,10 times, total 3 sessions, total 30 treatments, n = 30)

(B) Drug therapy (Bandazol, Dextran 40, Danshen tablet, and vitamin B12, 10 days, total 3 sessions, n = 30)

Response rate (verbal description of any changes)

RR, 2.20 [1.27, 3.89], P < 0.05

Parallel

1 week-10years

(C) Herbal medicine (n = 30)

China

Jiang (2010) [23]

60 senile tinnitus (n.r.)

50-80 (21/39)

(A) AT (n.r., 1 session = 30 min, once daily, 5 times, rest for 2 days, 10 times/session, total 3 sessions, total 30 treatments, n = 30)

(B) Drug therapy (Flunarizine hydrochloride 10mg, orally at bedtime, 4weeks, stop taking without any improvements, effective service by adding 2 weeks, n = 30)

1) Hearing-threshold detection

1) MD, 0.28[-4.67,5.23], NS^‡

Parallel

n.r.

2) Activities of daily living (tinnitus, auditory, concomitant symptoms)

2) Tinnitus, MD, -0.75 [-1.10, -0.40], P < 0.0001; auditory, MD, -0.73 [-1.25, -0.21], P = 0.006; concomitant symptoms, MD, -0.27[-0.57, 0.03], NS

China

3) Response rate (verbal description of any changes)

3) RR, 1.14 [0.87, 1.49], NS