Table 2

Multilevel models predicting perceived message effectiveness (PME) for message themes

	k	Overall		Vaped in past 30 days		Susceptible to vaping		Non-susceptible to vaping
		N=1501		n=464		n=649		n=388
		b	95% CI	b	95% CI	b	95% CI	b	95% CI
Intercept		3.28**	3.19 to 3.37	3.05**	2.95 to 3.14	3.21**	3.14 to 3.28	3.77**	3.67 to 3.87
Message themes
Nicotine addiction	70	0.25**	0.21 to 0.29	0.12*	0.05 to 0.19	0.35**	0.28 to 0.41	0.26**	0.18 to 0.34
Uses the word ‘nicotine’	62	0.31**	0.27 to 0.35	0.18**	0.11 to 0.25	0.4**	0.33 to 0.47	0.33**	0.25 to 0.42
Uses the word ‘addiction’	40	0.14**	0.09 to 0.19	0.06	−0.02 to 0.14	0.17**	0.09 to 0.25	0.2**	0.10 to 0.29
Chemicals	66	0.42**	0.38 to 0.46	0.34**	0.27 to 0.41	0.45**	0.45 to 0.58	0.35**	0.28 to 0.43
Specific chemical name	46	0.37**	0.32 to 0.42	0.31**	0.23 to 0.39	0.45**	0.37 to 0.52	0.3**	0.21 to 0.38
Uses the word ‘chemical’	34	0.4**	0.35 to 0.46	0.28**	0.19 to 0.36	0.5**	0.42 to 0.59	0.39**	0.30 to 0.49
Chemical ‘also found in’	19	−0.09*	−0.18 to −0.001	−0.11	−0.26 to 0.05	−0.03	−0.18 to 0.11	−0.16	−0.33 to 0.01
Health effects on organs (brain, lungs)	52	0.4**	0.36 to 0.44	0.32**	0.24 to 0.39	0.49**	0.42 to 0.56	0.35**	0.26 to 0.43
Affects lungs†	31	0.002	−0.08 to 0.08	0.16*	0.02 to 0.30	−0.07	−0.20 to 0.05	−0.11	−0.27 to 0.06
Affects brain†	23	0.1*	0.02 to 0.18	−0.1	−0.24 to 0.04	0.17*	0.05 to 0.32	0.23*	0.07 to 0.39
Industry targeting	42	−0.23**	−0.28 to −0.18	−0.16**	−0.24 to −0.08	−0.3**	−0.39 to −0.22	−0.18**	−0.27 to −0.09
Flavours	29	−0.25**	−0.31 to −0.20	−0.23**	−0.32 to −0.13	−0.31**	−0.40 to −0.22	−0.18*	−0.29 to −0.07
Comparison to cigarettes	27	0.31**	0.25 to 0.37	0.19**	0.09 to 0.29	0.42**	0.33 to 0.51	0.28**	0.17 to 0.39
Health-related symptoms	25	0.37**	0.31 to 0.43	0.26**	0.15 to 0.36	0.48**	0.39 to 0.58	0.33**	0.22 to 0.45
Not harmless water vapour	48	0.17**	0.10 to 0.24	0.004	−0.11 to 0.12	0.28**	0.17 to 0.39	0.23*	0.09 to 0.36
Death	12	0.25**	0.16 to 0.33	0.31**	0.16 to 0.46	0.27**	0.13 to 0.42	0.13	−0.02 to 0.29
Unknown ingredients or health effects	10	0.25**	0.16 to 0.34	0.17*	0.02 to 0.33	0.32**	0.16 to 0.47	0.22*	0.05 to 0.39
Environmental impact	10	−0.32**	−0.41 to −0.22	−0.21*	−0.37 to −0.06	−0.47**	−0.62 to −0.32	−0.19*	−0.36 to −0.01
Sharing vapes can spread germs	6	0.11	−0.01 to 0.23	0.13	−0.07 to 0.33	0.09	−0.10 to 0.28	0.13	−0.11 to 0.37
Gateway to cigarette/tobacco use	5	0.55**	0.42 to 0.67	0.43**	0.22 to 0.65	0.68**	0.48 to 0.88	0.45**	0.21 to 0.69

Outcome is composite score for three-item PME scale: 1=not at all, 2=very little, 3=somewhat, 4=quite a bit, 5=very much (ɑ=0.93); *p<0.05, **p<0.001. Models adjusted for gender, age, race, ethnicity, maternal education, cigarette use and use of one or more other tobacco products.
†Coded if “health effects on organs” was “yes”.