Table 3:

Main and interaction effects of product attributes on outcomes

Product attributes	Interest, n=1713	Perceived harmfulness, n=1952
Product attributes	coef. (SE)	coef. (SE)

Model 1: Main effects

Product Type
cigarette	Ref	Ref
heated tobacco	−0.93 (0.19)^***	2.77 (0.21)^***
e-cigarette	1.22 (0.12)^***	−1.47 (0.24)^***
Brand
0	Ref	Ref
1	−0.02 (0.03)	0.11 (0.03)^***
Nicotine
12 mg	Ref	Ref
none	0.14 (0.03)^***	0.20 (0.04)^***
Flavor
tobacco	Ref	Ref
menthol	0.17 (0.04)^***	0.03 (0.04)
cherry	0.24 (0.04)^***	0.14 (0.04)^***
berry	0.28 (0.04)^***	−0.01 (0.05)

Model 2: Product type by Nicotine interaction

Product type x Nicotine
cigarette, 12 mg	Ref	Ref
cigarette, without nicotine	−0.12 (0.05)^*	1.02 (0.07)^***
HTP, 12 mg	−0.94 (0.19)^***	2.97 (0.22)^***
HTP, without nicotine	−1.05 (0.20)^***	3.68 (0.22)^***
e-cigarette, 12 mg	0.77 (0.13)^***	0.27 (0.27)
e-cigarette, without nicotine	1.30 (0.12)^***	−1.70 (0.29)^***
Overall p-value	<0.001	<0.001

Model 3: Product type by Flavor interaction

Product type x Flavor
cigarette, tobacco	Ref	Ref
cigarette, menthol	−0.06 (0.06)	0.23 (0.08)^***
cigarette, cherry	−0.06 (0.07)	0.26 (0.07)^***
cigarette, berry	−0.06 (0.07)	0.06 (0.09)
HTP, tobacco	−0.69 (0.20)^***	2.77 (0.22)^***
HTP, menthol	−1.05 (0.20)^***	2.93 (0.22)^***
HTP, cherry	−1.13 (0.21)^***	3.11 (0.22)^***
HTP, berry	−1.15 (0.21)^***	2.84 (0.22)^***
e-cigarette, tobacco	0.56 (0.13)^***	−1.07 (0.26)^***
e-cigarette, menthol	1.19 (0.13)^***	−1.53 (0.25)^***
e-cigarette, cherry	1.37 (0.13)^***	−1.39 (0.25)^***
e-cigarette, berry	1.49 (0.13)^***	−1.29 (0.25)^***
Overall p-value	<0.001	<0.001

Coef. = coefficient; SE = standard error; Ref = reference level;

p < 0.05;

^**

p < 0.01;

^***

p < 0.001

All models adjust for block. Interaction models also include the attributes not present in the interaction.