Table 2.

Association between e-cigarette warning exposure and knowledge of whether e-cigarettes contain nicotine, among ever e-cigarette users.

	Prevalence and odds of knowing whether e-cigarettes used contain nicotine, among ever users
	%	AOR	95% CI		p-value
Warning exposure
Yes	84.2	2.26	1.67	3.06	<0.001
No/don't know	69.8	ref
Country
US	76.1	1.06	0.82	1.36	0.673
England	68.0	0.71	0.55	0.92	0.009
Canada	74.0	ref
Sex
Male	74.4	1.27	1.06	1.53	0.011
Female	70.2	ref
Age
16–17	67.6	0.69	0.57	0.84	<0.001
18–19	75.6	ref
Race/ethnicity
White	73.1	1.14	0.93	1.39	0.209
Other/mixed	71.9	ref