Table 1.

Comparison of the verum and the sham laser group, first and second treatment day and impact of expectancy effects due to acupuncture experience and belief in laser acupuncture

	Occurrence of deqii)	Intensity of deqiii) (± SD)	Laser assumed to be activeiii)	Correct identificationsiii)
verum laser (n = 34)	47/102	2.34 ± 2.34	12/34	12/34
sham laser (n = 34)	50/102	2.49 ± 2.36	15/34	17/34
p-value	0.67	0.71	0.45	0.21
day 1 n = 34	55/102	2.39 ± 2.45	17/34	15/34
day 2 n = 34	42/102	2.46 ± 2.22	10/34	14/34
p-value	0.07	0.69	0.18	0.84
acupuncture-experienced n = 17	53/102	3.24 ± 2.65	14/34	12/34
acupuncture-naïve n = 17	44/102	1.43 ± 1.37	13/34	17/34
p-value	0.21	0.0002	0.97	0.14
convinced n = 14	44	2.23 ± 1.80	13/28	12/28
not convinced n = 20	53/120	2.57 ± 2.72	14/40	17/40
p-value	0.25	0.72	0.30	0.91

Statistical analysis was performed by using the chi-square-test according to Pearson for occurrence of deqi sensations, for how often the laser device was assumed to be active and for the number of correct identifications. The Mann-Whitney-U test was used to compare the intensity of deqi sensations (evaluated by VAS). Subjects were treated at two treatment sessions at three different acupuncture points. Therefore, occurrence of deqi sensations is depicted relative to the number of point treatments calculated as n times six. Subjects were asked whether they considered the laser device active or inactive after each treatment session, hence correct identifications and the estimations that the laser was active apply to the total number of treatments calculated as n times 2.