Table. Prevalence of Marijuana Use in Electronic Cigarettes Among US Youth, 2017-2018 National Youth Tobacco Survey (N = 38 061).
| Prevalence of Marijuana Use in e-Cigarettes, Weighted % (95% CI)a,b | Change Across Years | |||
|---|---|---|---|---|
| 2017 (n = 17 872) | 2018 (n = 20 189) | 2018 vs 2017, Weighted % (95% CI)a | P Valuec | |
| Overall | 11.1 (9.8 to 12.5) | 14.7 (13.3 to 16.1) | 3.6 (1.6 to 5.5) | <.001 |
| Sex | ||||
| Male | 11.2 (9.8 to 12.5) | 14.6 (13.2 to 16.0) | 3.4 (1.5 to 5.3) | <.001 |
| Female | 10.9 (9.4 to 12.5) | 14.7 (13.0 to 16.4) | 3.8 (1.4 to 6.1) | .007 |
| Age, y | ||||
| 9-12 | 3.0 (2.1 to 3.9) | 2.8 (2.1 to 3.6) | −0.2 (−1.3 to 1.0) | .54 |
| 13-15 | 8.3 (7.2 to 9.5) | 11.1 (9.9 to 12.3) | 2.7 (1.1 to 4.4) | .004 |
| 16-17 | 18.0 (15.8 to 20.1) | 24.1 (21.8 to 26.4) | 6.1 (3.0 to 9.3) | <.001 |
| ≥18 | 23.0 (19.1 to 26.8) | 28.3 (25.3 to 31.4) | 5.4 (0.4 to 10.3) | .09 |
| Grade | ||||
| Middle school | 4.5 (3.7 to 5.2) | 5.5 (4.5 to 6.5) | 1.0 (−0.2 to 2.2) | .15 |
| High school | 16.1 (14.2 to 18.0) | 21.7 (20.1 to 23.3) | 5.6 (3.1 to 8.1) | <.001 |
| Race/ethnicityd | ||||
| Non-Hispanic white | 10.8 (9.2 to 12.3) | 14.5 (12.6 to 16.4) | 3.7 (1.3 to 6.2) | .002 |
| Non-Hispanic black | 10.5 (8.8 to 12.3) | 11.6 (9.3 to 13.8) | 1.1 (−1.8 to 3.9) | .63 |
| Hispanic | 14.1 (12.1 to 16.0) | 18.4 (16.2 to 20.6) | 4.3 (1.5 to 7.2) | .007 |
| Other | 5.5 (3.4 to 7.7) | 8.8 (6.6 to 11.0) | 3.3 (0.2 to 6.4) | .18 |
| Ever users of e-cigarettese | 37.2 (34.0 to 40.4) | 42.7 (40.2 to 45.3) | 5.5 (1.4 to 9.6) | .01 |
| Current use of e-cigarettesf | ||||
| No | 7.4 (6.6 to 8.1) | 8.1 (7.0 to 9.2) | 0.7 (−0.6 to 2.1) | .31 |
| Yes | 51.7 (46.1 to 57.3) | 53.5 (50.2 to 56.8) | 1.8 (−4.7 to 8.3) | .42 |
| No. of days e-cigarettes used in past 30 d, df | ||||
| 1-5 | 43.6 (38.0 to 49.2) | 43.2 (39.2 to 47.2) | −0.3 (−7.2 to 6.6) | .98 |
| 6-19 | 56.3 (47.6 to 65.1) | 56.7 (51.3 to 62.2) | 0.4 (−9.9 to 10.7) | .98 |
| 20-30 | 72.6 (64.3 to 80.8) | 70.9 (66.6 to 75.2) | −1.7 (−11.0 to 7.7) | .63 |
| Current cigarette smokingg | ||||
| No | 8.1 (7.1 to 9.2) | 11.4 (10.1 to 12.7) | 3.3 (1.6 to 4.9) | <.001 |
| Yes | 56.2 (50.3 to 62.1) | 63.4 (59.3 to 67.6) | 7.2 (0.0 to 14.4) | .11 |
| Current use of other tobacco productsh | ||||
| No | 7.3 (6.3 to 8.3) | 10.4 (9.2 to 11.6) | 3.1 (1.5 to 4.7) | <.001 |
| Yes | 53.3 (48.9 to 57.7) | 56.6 (52.8 to 60.4) | 3.3 (−2.5 to 9.1) | .33 |
| No. of tobacco products currently usedh | ||||
| 0 | 5.5 (4.8 to 6.2) | 6.4 (5.6 to 7.3) | 1.0 (−0.2 to 2.1) | .10 |
| 1 (single use) | 33.2 (29.1 to 37.2) | 40.6 (36.6 to 44.5) | 7.4 (1.8 to 13.1) | .02 |
| 2 (dual use) | 56.5 (49.8 to 63.2) | 57.1 (51.8 to 62.5) | 0.6 (−8.0 to 9.2) | .87 |
| ≥3 (poly use) | 65.8 (60.1 to 71.5) | 71.6 (67.7 to 75.4) | 5.8 (−1.1 to 12.6) | .04 |
| Tobacco use by household membersi | ||||
| None | 7.6 (6.3 to 8.9) | 10.5 (9.0 to 12.0) | 2.9 (1.0 to 4.9) | .003 |
| e-Cigarettes | 22.7 (18.8 to 26.6) | 29.5 (27.1 to 32.0) | 6.8 (2.2 to 11.4) | .007 |
| Other tobacco products | 15.2 (13.5 to 17.0) | 17.8 (15.7 to 19.9) | 2.5 (−0.2 to 5.3) | .04 |
Weighted estimates and 95% CIs were reported by taking the complex survey design (sampling weight, stratum, and cluster) into account using the Taylor series variance estimation.
In the 2017 and 2018 National Youth Tobacco Surveys, marijuana use in e-cigarettes was assessed by the response yes to the question “Have you ever used marijuana, marijuana concentrates, marijuana waxes, THC, or hash oils in an e-cigarette?”
Multivariable logistic regression was performed, in which ever marijuana use in e-cigarettes (yes vs no) was the outcome variable, year (2017-2018, categorical) was the predictive variable, and covariates included age, sex, race/ethnicity, and tobacco use by a household member.
Race and Hispanic ethnicity were self-reported, and Hispanic persons could be of any race.
Ever e-cigarette use was assessed by the question “Have you ever used an e-cigarette, even once or twice?”
Current e-cigarette use and No. of days e-cigarettes used were assessed by the question “During the past 30 days, on how many days did you use e-cigarettes?”
Defined as students who reported smoking cigarettes 1 or more days in the past 30 days.
Defined as students who reported use of cigars, little cigars, or cigarillos; pipes filled with tobacco; bidis; hookah or waterpipe; smokeless tobacco (ie, chewing tobacco, snuff or dip, snus, dissolvable tobacco products) 1 or more days in the past 30 days for any listed product.
Defined by the question “Does anyone who lives with you now…? (Select one or more).”