Table 4.

Subgroup analyses on the prevalence of xerostomia among e-cigarette or combustible tobacco users

Variables	Number of studies	% (95% CI)	p	Heterogeneity
				I2 (%)	p
All studies	14	26 (18–35)	<0.001	99	<0.001
Type of smoking
E-cigarette	8	33 (18–48)	<0.001	99	<0.001
Combustible tobacco	3	24 (21–27)	<0.001	95	<0.001
Country
USA	3	39 (37–40)	<0.001	99	<0.001
Saudi Arabia	3	21 (18–24)	<0.001	84	0.002
Pakistan	2	13 (10–15)	<0.001	68	0.077
Age (years)
<25	6	30 (28–32)	<0.001	99	<0.001
25–65	3	20 (18–23)	<0.001	90	<0.001