TABLE 3

Relationships between exposure to e-cigarette advertisements and past 30-day use of electronic cigarettes, combustible cigarettes and hookahs

Outcomes (dichotomous) current use^#	E-cigarette use^¶	Cigarette use⁺	Hookah use^§	E-cigarette/cigarette use^ƒ	E-cigarette/hookah use^##	Cigarette/hookah use^¶¶	E-cigarette/cigarette/hookah use⁺⁺
Exposure to e-cigarette advertisements	2.3 (1.6–3.2)***	1.4 (1.1–1.9)*	1.3 (1.0–1.7)*	2.4 (1.5–4.1)***	2.2 (1.5–3.4)***	1.8 (1.1–2.9)*	3.4 (1.8–6.5)***
Age	1.3 (1.1–1.5)***	1.6 (1.4–1.8)***	1.4 (1.3–1.5)***	1.5 (1.2–1.8)***	1.3 (1.1–1.5)*	1.6 (1.3–1.9)***	1.8 (1.5–2.2)***
Sex (ref=female)	1.2 (0.9–1.7)	0.5 (0.4–0.6)***	1.0 (0.7–1.3)	0.5 (0.3–0.9)*	1.0 (0.7–1.5)	0.5 (0.3–0.9)*	0.4 (0.2–0.8)*
School type (ref=high)	2.1 (1.3–3.3)*	1.5 (0.9–2.5)	1.7 (1.1–2.6)*	2.2 (1.2–3.9)*	3.1 (1.7–5.5)***	1.4 (0.8–2.4)	2.8 (1.3–6.1)*
Migration background (ref=none)	0.9 (0.6–1.4)	0.4 (0.3–0.7)***	2.2 (1.6–3.0)***	0.4 (0.2–0.9)*	1.3 (0.8–2.0)	0.8 (0.4–1.3)	0.5 (0.2–1.2)
Socioeconomic status (ref=low)	1.1 (1.0–1.3)	0.9 (0.8–1.0)	1.1 (1.0–1.2)*	1.0 (0.9–1.2)	1.0 (1.0–1.3)	1.0 (0.9–1.2)	1.1 (0.9–1.3)
Sensation seeking (ref=low)	2.2 (1.9–2.6)***	1.8 (1.5–2.1)***	1.7 (1.5–1.9)***	2.8 (2.2–3.7)***	2.4 (2.0–2.9)***	2.3 (1.8–3.0)***	3.9 (2.8–5.5)***
Consumer susceptibility (ref=low)	1.1 (0.9–1.4)	1.1 (0.9–1.3)	1.3 (1.1–1.5)*	1.2 (0.9–1.6)	1.2 (0.9–1.5)	1.6 (1.2–2.1)***	1.3 (0.9–1.9)
E-cigarette use		7.7 (5.4–11.1)***	8.4 (5.8–12.3)***			11.5 (5.3–25.3)***
At least one friend vaping e-cigarettes^§§	18.1 (6.2–52.6)***	1.0 (0.7–1.6)	1.8 (1.1–3.0)*	30.3 (3.8–240.5)***	30.5 (4.0–231.1)***	3.9 (1.5–10.3)*
At least one friend smoking cigarettes^§§	2.3 (1.3–4.3)*	38.9 (9.3–163.1)***	1.4 (0.9–2.2)		1.7 (0.8–3.6)
At least one friend smoking hookahs^§§	1.9 (0.9–4.2)	1.8 (1.0–3.2)*	11.5 (4.4–33.0)***	2.0 (0.6–7.2)	5.2 (1.2–22.6)*

Data are presented as adjusted odds ratio (95% CI). ref: reference. ^#: models adjusted for age, sex, migration background, school type, consumer susceptibility to interpersonal influence, socioeconomic status, sensation seeking, and e-cigarette use of at least one friend; ^¶: n=6577; ⁺: n=6531; ^§: n=6529; ^ƒ: n=6540; ^##: n=6533; ^¶¶: n=6532; ⁺⁺: n=6575; ^§§: peer behaviour was omitted in some cases due to small cell frequencies, meaning that corresponding behaviour was also shown by peers. *: p<0.05; ***: p≤0.001; all models allow for nested data (p<0.05).