The Nonpenetrating Telescopic Sham Needle May Blind Patients with Different Characteristics and Experiences When Treated by Several Therapists

Table 4

The ability to identify if verum or sham acupuncture was given in patients treated by several therapists in two hospitals.

Subgroup		Stated: Penetrating the skin^1	Stated: Placed against the skin^1	Not sure at all, guessed	Bang’s blinding index^2 (95% Confidence interval)	𝑃 value multivariate analysis^3
Blinding, by hospital	𝑛=190					.425
Verum acupuncture 𝑛 (%)
at hospital A	𝑛=60	49 (82)	3 (5)	8 (13)	0.77 (0.63–0.90)
at hospital B	𝑛=35	25 (71)	3 (9)	7 (20)	0.63 (0.42–0.84)
Sham acupuncture 𝑛 (%)
at hospital A	𝑛=69	54 (78)	7 (10)	8 (12)	−0.68 (−0.83–−0.53)
at hospital B	𝑛=26	14 (54)	4 (15)	8 (31)	−0.38 (−0.67–−0.10)
Blinding, by therapists						.434
Verum acupuncture 𝑛 (%)
by one therapist (A1)	𝑛=41	35 (85)	0 (0)	6 (15)	0.85 (0.75–0.96)
by one therapist (B1)	𝑛=9	7 (88)	0 (0)	2 (12)	0.78 (0.51–1.05)
by two therapists (A1 and A2/A3/A4)	𝑛=19	14 (74)	3 (16)	2 (11)	0.58 (0.24–0.92)
by two therapists (B1 and B2/B3)	𝑛=22	15 (68)	2 (9)	5 (23)	0.59 (0.32–0.86)
by three therapists (A1 and A2/A3/A4)	𝑛=0	0 (0)	0 (0)	0 (0)	—^4
by three therapists (B1, B2 and B3)	𝑛=4	3 (75)	1 (25)	0 (0)	—^4
Sham acupuncture 𝑛 (%)
by one therapist (A1)	𝑛=40	31 (78)	4 (10)	5 (13)	−0.68 (−0.87–−0.47)
by one therapist (B1)	𝑛=4	2 (50)	0 (0)	2 (50)	−0.50 (−0.99–−0.01)
by two therapists (A1 and A2/A3/A4)	𝑛=29	23 (79)	3 (10)	3 (10)	−0.69 (−0.93–−0.45)
by two therapists (B1 and B2/A3)	𝑛=21	11 (28)	4 (11)	6 (29)	−0.33 (−0.67–−0.00)
by three therapists (A1 and A2/A3/A4)	𝑛=0	0 (0)	0 (0)	0 (0)	—^4
by three therapists (B1 and B2/B3)	𝑛=1	1 (100)	0 (0)	0 (0)	—^4

¹The individuals were fairly or entirely sure of their answer. ²Correct answers/total 𝑛—incorrect answers/total 𝑛. The number (𝑛) of patients answering the questions is presented. Total 𝑛=190 of the entering 215 patients (18 interrupted radiotherapy and/or verum/sham acupuncture and 7 did not provide blinding data). ³Including the variables seen in Tables 4–6 and received needling type. ⁴Blinding index was not calculated due to low 𝑛 within the subgroup (𝑛<5). Therapist A1 = main therapist at hospital A. Therapist A2, A3, A4 = deputy therapists on hospital A.Therapist B1 = main therapist at hospital B. Therapist B2, B3 = deputy therapists on hospital B.