Table 1.
Sample Characteristics and Outcomes by Level of Electronic Cigarette Usea
| n b | Non-use/trial (n = 364) % (CI) | Intermittent use (n = 220) % (CI) | Intensive use (n = 111) % (CI) | Total (N = 695) % (CI) | p | |
| Gender | ||||||
| Male | 398 | 45.8 (30.1, 62.3) | 47.6 (21.3, 75.4) | 84.1 (59.9, 94.9) | 55.2 (40.3, 69.2) | .06 |
| Female | 297 | 54.2 (37.7, 69.9) | 52.4 (24.6, 78.7) | 15.9 (5.1, 40.1) | 44.8 (30.8, 59.7) | |
| Age group (y) at baseline | ||||||
| 18–30 | 90 | 12.3 (5.0, 27.1) | 8.6 (3.1, 21.8) | 30.9 (8.6, 68.1) | 15.5 (7.6, 29.1) | .42 |
| 31–49 | 197 | 50.9 (34.3, 67.3) | 47.6 (20.0, 76.7) | 48.6 (20.2, 77.9) | 49.4 (35.3, 63.5) | |
| 50–65 | 408 | 36.8 (23.1, 53.0) | 43.8 (19.6, 71.4) | 20.5 (7.1, 46.5) | 35.1 (24.2, 47.7) | |
| Education at baseline | ||||||
| < BA | 529 | 67.5 (51.1, 80.6) | 45.7 (20.7, 73.2) | 72.8 (45.1, 89.7) | 62.5 (47.4, 75.5) | .27 |
| ≥ BA | 165 | 32.5 (19.4, 48.9) | 54.3 (26.8, 79.3) | 27.2 (10.3, 54.9) | 37.5 (24.5, 52.6) | |
| Race/ethnicity | ||||||
| Minority | 121 | 19.6 (10.6, 33.5) | 16.5 (6.0, 38.0) | 53.8 (25.2, 80.1) | 26.6 (15.5, 41.8) | .02 |
| White/non-Hispanic | 572 | 80.4 (66.5, 89.4) | 83.5 (62.0, 94.0) | 46.2 (19.9, 74.8) | 73.4 (58.2, 84.5) | |
| Heavy smoker, baseline | ||||||
| Yes | 240 | 20.6 (11.4, 34.4) | 28 (11.3, 54.2) | 68.2 (40.3, 87.2) | 33.9 (21.6, 48.7) | .01 |
| No | 448 | 79.4 (65.6, 88.6) | 72 (45.8, 88.7) | 31.8 (12.8, 59.7) | 66.1 (51.3, 78.4) | |
| Smoking cessation | ||||||
| Quitter | 130 | 12.4 (5.1, 26.9) | 8.5 (2.4, 25.9) | 20.4 (7.3, 45.5) | 13.1 (7.3, 22.3) | .5 |
| Smoker | 565 | 87.6 (73.1, 94.9) | 91.5 (74.1, 97.6) | 79.6 (54.5, 92.7) | 86.9 (77.7, 92.7) | |
| Changes in readiness to quit c | ||||||
| Decreased | 110 | 26.8 (12.6, 48.3) | 46.6 (17.8, 77.9) | 62.8 (28.0, 88.0) | 39.2 (23.7, 57.2) | .24 |
| Same or increased | 430 | 73.2 (51.7, 87.4) | 53.4 (22.1, 82.2) | 37.2 (12.0, 72.0) | 60.8 (42.8, 76.3) | |
| Changes in likelihood of being quit in one year c | ||||||
| Decreased likelihood | 125 | 14.3 (7.0, 26.9) | 52.7 (23.8, 80.0) | 11.7 (2.8, 37.8) | 25.4 (12.5, 44.8) | .01 |
| Increased likelihood | 427 | 85.7 (73.1, 93.0) | 47.3 (20.0, 76.2) | 88.3 (62.2, 97.2) | 74.6 (55.2, 87.5) | |
aNon-use/trial = never used or used one or two times; intermittent use = used more than twice but not daily for 1+ months; intensive use = used daily for 1+ months.
b Ns are unweighted; percentages are weighted. CI = 95% confidence interval.
cIncludes only those continuing to smoke.