Short-Term Efficacy of Pulsed Radiofrequency Thermal Stimulation on Acupoints for Chronic Low Back Pain: A Preliminary Study of a Randomized, Single-Blinded, Placebo-Controlled Trial

Table 2

Mean change compared to the baseline and the mean difference in change between the treatment and placebo-controlled groups at each visit for the primary and secondary outcomes.

	Treatment		Placebo-controlled		Treatment–Placebo-controlled
	Mean change from the baseline (95% CI)	p value	Mean change from the baseline (95% CI)	p value	Adjusted mean difference between the groups (95% CI)	p value
VAS [mm]
Visit 1 – Baseline	0.357; (-3.448, 4.162)	0.9935	0.000; (-3.805, 3.805)	1.0000	0.118; (-0.384, 0.620)	0.6811
Visit 2 – Baseline	-2.857; (-6.662, 0.948)	0.3837	-3.036; (-6.841, 0.769)	0.3324	-1.299; (-5.949, 3.351)	0.2886
Visit 3 – Baseline	-5.000; (-8.805, -1.195)	0.0366	-9.107; (-12.912, -5.302)	<0.0001	1.826; (-4.664, 8.316)	0.7127
Visit 4 (F/U) – Baseline§	-8.036; (-11.841, -4.231)	0.0002	-13.393; (-17.198, -9.588)	<0.0001	2.015; (-5.288, 9.317)	0.7090
PPT [kg/cm^2]
Visit 2 – Visit 1	-1.294; (-1.804, -0.784)	<0.0001	-0.878; (-1.388, -0.367)	0.0025	-0.581; (-1.308, 0.146)	0.0575
Visit 3 – Visit 1	-1.367; (-1.877, -0.857)	<0.0001	-1.020; (-1.530, -0.509)	0.0003	-0.417; (-1.087, 0.253)	0.1087
Visit 4 (F/U) – Visit 1§	-1.421; (-1.932, -0.911)	<0.0001	-0.935; (-1.445, -0.425)	0.0012	-0.507; (-1.217, 0.203)	0.0789
PGIC
Visit 4 (F/U) – Visit 1§	-0.786; (-1.115, -0.457)	<0.0001	-0.929; (-1.258, -0.600)	<0.0001	0.053; (-0.419, 0.525)	0.5887
EQ-5D
Visit 4 (F/U) – Visit 1§	0.026; (0.000, 0.052)	0.0485	0.050; (0.024, 0.076)	<0.0001	-0.022; (-0.056, 0.012)	0.9038

Data are summarized as the mean and 95% CI for the primary and secondary outcomes.
Result of the within-groups analysis using a linear mixed effects model; p values were adjusted with Dunnett’s test.
Result of the between-groups analysis using an ANCOVA with the following covariates: the baseline value, age, patient’s duration of LBP, and compliance of daily exercise.
§Follow-up end point.
CI: confidence interval; VAS: visual analogue scale; PPT: pressure pain threshold; PGIC: patient global impression of change; EQ-5D: Euro Quality of Life-5 Dimensions.