TABLE 1.
Characteristic | E-Cigarette–Only Users,a n = 67, Mean (SD) or No. (%) | Dual Users,b n = 16, Mean (SD) or No. (%) | Controls, n = 20, Mean (SD) or No. (%) | Pc |
---|---|---|---|---|
Age | 16.3 (1.2) | 17.1 (0.96) | 16.0 (1.8) | .06 |
Sex (male) | 49 (73%) | 12 (80%) | 7 (35%) | <.01 |
Race and/or ethnicity | <.01 | |||
Non-Hispanic white | 36 (54%) | 9 (67%) | 0 | |
Asian American or Pacific Islander | 12 (19%) | 2 (12%) | 2 (10%) | |
Multiracial | 10 (15%) | 3 (19%) | 0 | |
Hispanic | 7 (10%) | 2 (12%) | 18 (90%) | |
Hours since last e-cigaretted | 1:58 (6:29) | 2:02 (7:17) | N/A | >.91 |
Days used in past 30 d | 12.8 (8.9) | 25.5 (6.6) | N/A | <.001 |
Sessions per day | 2.0 (3.6) | 8.4 (11.6) | N/A | .05 |
Usual puffs per session | N/A | .49 | ||
1–4 | 14 (21%) | 1 (7%) | ||
5–10 | 21 (31%) | 4 (27%) | ||
10–15 | 11 (16%) | 4 (27%) | ||
>15 | 21 (31%) | 6 (40%) | ||
Usual length of session | N/A | .97 | ||
1–2 min | 8 (12%) | 2 (13%) | ||
3–5 min | 16 (24%) | 4 (27%) | ||
6–10 min | 16 (24%) | 4 (27%) | ||
>10 min | 27 (40%) | 5 (33%) | ||
Usual type of device | N/A | .82 | ||
Vape pen | 24 (36%) | 6 (40%) | ||
Modified | 17 (25%) | 4 (27%) | ||
Juul | 18 (27%) | 4 (27%) | ||
Other or unsure | 8 (12%) | 1 (7%) | ||
E-cigarettes contain nicotine | N/A | .06 | ||
Always | 21 (31%) | 9 (60%) | ||
Sometimes | 26 (39%) | 6 (40%) | ||
Unsure | 10 (15%) | 0 (0%) | ||
Never | 10 (15%) | 0 (0%) | ||
Usual flavor of e-cigarettee | N/A | |||
Fruit | 37 (55%) | 10 (67%) | .42 | |
Candy | 11 (16%) | 2 (13%) | .77 | |
Menthol | 12 (18%) | 2 (13%) | .67 | |
Tobacco | 5 (8%) | 2 (13%) | .46 |
N/A, not applicable.
Used an e-cigarette product in the past 24 h and had NNAL levels <1 ppm of creatinine.
Used an e-cigarette product in the past 24 h, smoked a cigarette in the past 30 d, and had NNAL levels ≥30 ppm of creatinine.
P values are the result of comparing 3 groups on age (analysis of variance), sex, and ethnicity (χ2); all e-cigarette characteristics are the result of comparing e-cigarette–only use to dual-use groups (t tests for continuous variables and χ2 analyses for categorical variables).
The median was reported because of non-normal distribution.
Participants could select >1.