Table 4.

Univariate and multivariate regression analysis of taVNS parameters associated with the number of AEs reported by patients undergoing active taVNS in the included studies.

	Beta-coefficient	95% CI	p-value
Univariate analysis
Age	0.001	− 0.002 to 0.006	0.422
Gender	0.275	− 0.037 to 0.588	0.082
Number of subjects	0.001	− 0.0003 to 0.004	0.099
Duration	0.151	0.049 to 0.252	0.004
Number of sessions	0.126	0.019 to 0.232	0.022
Intensity	0.070	− 0.067 to 0.208	0.312
Frequency	0.083	− 0.032 to 0.199	0.155
Pulse width	− 0.129	− 0.284 to 0.024	0.096
Side	− 0.058	− 0.230 to 0.114	0.501
Devices	0.149	0.010 to 0.289	0.036
Multivariate analysis			R2 = 0.1882
Age	-0.5e-5	− 3e-5 to 2e-5	0.727
Gender	0.053	− 0.113 to 0.220	0.520
Duration	0.285	0.122 to 0.448	0.001

CI: confidence interval.