Table 2.
E-cigarette use according to smoking status.
| Tobacco-Smoking 1 | p * | ||||
|---|---|---|---|---|---|
| All Students 2 n = 2706 | Never Smokers n = 1160 | Former Smokers n = 241 | Current Smokers n = 1305 | ||
| n (%) | n (%) | n (%) | n (%) | ||
| E-cigarette use 3 | <0.0001 | ||||
| Never use | 1621 (59.9) | 1003 (86.5) | 66 (27.4) | 552 (42.3) | |
| Former use | 987 (36.5) | 153 (13.2) | 146 (60.6) | 688 (52.7) | |
| Current use | 98 (3.6) | 4 (0.3) | 29 (12.0) | 65 (5.0) | |
| Test sequence of tobacco and e-cigarette 4,5 | n = 550 | n = 80 | n = 470 | 0.0009 | |
| E-cigarette before tobacco | 18 (3.3) | - | 3 (3.7) | 15 (3.2) | |
| E-cigarette and tobacco the same year | 40 (7.3) | - | 6 (7.5) | 34 (7.2) | |
| E-cigarette after tobacco | 492 (89.4) | - | 71 (88.8) | 421 (89.6) | |
| Nicotine in cartridges 6 | n = 98 | n = 4 | n = 29 | n = 65 | 0.0152 γ |
| Only e-liquids with nicotine | 7 (7.1) | 0 (0.0) | 1 (3.5) | 6 (9.2) | |
| Only nicotine-free e-liquids | 61 (62.3) | 0 (0.0) | 17 (58.6) | 44 (67.7) | |
| Both | 19 (19.4) | 4 (100.0) | 6 (20.7) | 9 (13.4) | |
| Unaware of nicotine in e-liquids | 11 (11.2) | 0 (0.0) | 5 (17.2) | 6 (9.2) | |
* Chi2- test and γ Fisher’s exact test. Missing data: 1 Smoking status: current smokers were those smoking occasionally (less than once a day) or daily at time of survey. Former smokers were those who did not smoke at time of study; 2 n = 14 (data missing on smoking status); 3 Electronic cigarette use: never e-cigarette users were those who had never tried it. Current users comprised those regularly using e-cigarettes at time of survey, daily, or occasionally (less of once a day). Former users were those who were not current smokers among experimenters, as opposed to current users; 4 n = 378 (data missing on age, in years, at which students tried tobacco and/or e-cigarettes); 5 Test sequence of tobacco and e-cigarette: explored in smokers and former smokers. Chi-2 test about difference between smokers and former smokers; 6 Nicotine in cartridges: this question was asked only to current users of e-cigarette (n = 98).