Table 10.

Meta-regression investigating the variables influencing the odds ratio between e-cigarette users and non-smokers

	Model 1		Model 2		Model 3		Model 4
Moderator	$\beta$	p	$\beta$	p	$\beta$	p	$\beta$	p
Axis section	−30.85	0.03	−12.34	0.39	−8.49	0.05	−12.06	0.01
Age of non-smokers	0.58	0.11
Age of e-cigarette smokers			0.10	0.80
Daily e-cigarette consumption					−0.02	0.94
Duration of e-cigarette consumption							0.98	0.43
QHeterogeneity	71.01	< 0.0001	117.98	< 0.0001	110.29	< 0.0001	97.92	< 0.0001
Qmoderator	2.48	0.11	0.06	0.80	0.00	0.94	0.63	0.43
I2	0.97		0.97		0.98		0.97
${\tau }^2$	19.59		29.84		30.13		26.48
R2	20.7		0.00		0.00		0.00