Randomized trial estimating effects of hypnosis versus progressive muscle relaxation on medical students’ test anxiety and attentional bias

Table 1 Characteristics of the participants and baseline comparison among three groups at pre-test

	Control (n = 45)		Hypnosis (n = 45)		PMR (n = 45)		Hypnosis & PMR vs control			Hypnosis vs PMR
	M	SD	M	SD	M	SD	t/χ2	P value	Cohen’s d/Cramer’s φ	t/χ2	P value	Cohen’s d/Cramer’s φ
Female, n	17		27		26		5.35	0.02	0.19	0.05	0.83	0.02
Age	20.94	0.94	20.76	1.05	20.84	0.85	0.13	0.90	0.08	-0.44	0.66	0.08
Education	14.71	0.84	14.80	1.14	14.96	0.82	-0.97	0.33	0.18	-0.76	0.45	0.16
SHSS	8.08	1.92	7.88	1.80	7.57	1.45	1.13	0.26	0.19	0.91	0.37	0.18
TAS score	8.66	1.33	23.74	1.63	23.97	2.42	45.03	< 0.001	8.77	0.53	0.60	0.11
STAI score
Trait	36.78	1.75	49.38	3.14	50.20	2.47	28.14	< 0.001	5.51	1.38	0.17	0.29
State	36.06	1.89	48.34	2.92	49.14	2.59	27.59	< 0.001	5.33	1.37	0.17	0.29
Speeded detection
Threatening words	-6.99	212.68	-381.10	159.76	-397.49	189.92	-10.37	< 0.001	1.89	-0.94	0.35	0.19
Positive words	-403.62	163.41	-219.88	170.82	-226.21	254.62	4.95	< 0.001	0.94	-0.14	0.89	0.03
Slowed disengagement
Threatening words	111.19	341.38	379.48	437.92	431.94	386.65	4.14	< 0.001	0.78	0.62	0.55	0.13
Positive words	100.93	291.41	-173.90	353.80	-113.31	403.44	-3.80	< 0.001	0.72	0.76	0.45	0.16

False Discovery Rate correction for multiple comparisons was applied to the P values.

PMR: Progressive muscle relaxation; SHSS: Stanford hypnotic susceptibility scale; STAI: State-Trait Anxiety Inventory; TAS: Test anxiety scale.

Table 2 Analysis of covariance comparing hypnosis and progressive muscle relaxation groups in post-test scores with pre-test as covariate

	Hypnosis (n = 45)		PMR (n = 45)		ANCOVA
	M	SD	M	SD	F	P value	η2
Speeded detection
threatening words	-346.00	279.88	-91.86	199.57	30.35	< 0.001	0.26
Positive words	-203.59	299.03	-300.54	242.72	10.03	0.002	0.10
Slowed disengagement
threatening words	260.04	398.21	387.18	420.11	3.36	0.070	0.04
Positive words	-4.78	369.07	-117.22	372.78	11.46	0.001	0.12
STAI scores
State	35.11	2.53	36.32	1.92	6.04	0.02	0.07
Trait	38.21	2.51	38.39	2.34	0.12	0.73	0.001

PMR: Progressive muscle relaxation; STAI: State-Trait Anxiety Inventory; ANCOVA: Analysis of covariance.