Table 3.

Association between the e-cigarette social environment and susceptibility to future cigarette use using the composite susceptibility index, restricted to never cigarette users, Children’s Health Study, N=1694^*

	Susceptibility to Cigarettes (composite index)
	N (Row %*)	OR (95%CI)†	OR (95%CI)††
Anyone living at home use e-cigarettes?
No	333 (21.8)	Ref	Ref
Yes	45 (30.0)	1.65 (1.13, 2.42)	1.50 (1.01, 2.21)
Number of friends who use e-cigarettes
0	227 (18.2)	Ref	Ref
1 or 2	64 (31.1)	2.10 (1.49, 2.95)	1.96 (1.38, 2.79)
3 or 4	45 (40.9)	2.91 (1.91, 4.42)	2.45 (1.52, 3.96)
Best friends’ reactions to e-cigarette use
Unfriendlya	178 (16.7)	Ref	Ref
Friendly	139 (32.3)	2.26 (1.73, 2.96)	2.15 (1.63, 2.84)
Very friendly	60 (33.7)	2.35 (1.64, 3.37)	2.20 (1.51, 3.19)

^*Total varies due to missing values

^†Adjusted for gender, ethnicity, income, highest parental education, and community

^††Additionally adjusted for e-cigarette use (never, non-current, current)

^aVery unfriendly or unfriendly