From: Preferences for different features of ENDS products by tobacco product use: a latent class analysis
 | TOTAL | CLASS 1 | CLASS 2 | CLASS 3 | CLASS 4 |
---|---|---|---|---|---|
 | n (%) or M ± SD | n (%) or M ± SD | n (%) or M ± SD | n (%) or M ± SD | n (%) or M ± SD |
ENDS PRODUCT USE | N = 636 | n = 169 | n = 159 | n = 147 | n = 161 |
ENDS use, past 30 days |  | 3, 4 |  | 1, 2 | 1 |
 No | 235 (36.9) | 80 (47.3) | 69 (43.4) | 45 (30.6) | 41 (25.5) |
 Yes | 401 (63.1) | 89 (52.7) | 90 (56.6) | 102 (69.4) | 120 (74.5) |
ENDS use, past 30 days with flavor(s) |  | 2 | 1 | . | . |
 No flavor use | 117 (18.4) | 24 (14.2) | 37 (23.3) | 32 (21.8) | 24 (14.9) |
 Flavor use | 284 (44.7) | 65 (38.5) | 53 (33.3) | 70 (47.6) | 96 (59.6) |
 No ENDS use | 235 (36.9) | 80 (47.3) | 69 (43.4) | 45 (30.6) | 41 (25.5) |
Thinks will use ENDS in the next year | Â | . | 3 | 2 | . |
 Definitely or probably not | 174 (27.4) | 46 (27.2) | 59 (37.1) | 34 (23.1) | 35 (21.7) |
 Definitely or probably yes | 462 (72.6) | 123 (72.8) | 100 (62.9) | 113 (76.9) | 126 (78.3) |
Ever tobacco product use | Â | 4 | . | . | 1 |
 Has never tried any tobacco products other than ENDS | 48 (7.5) | 7 (4.1) | 8 (5.0) | 12 (8.2) | 21 (13.0) |
 Has tried at least one tobacco product other than ENDS | 588 (92.5) | 162 (95.9) | 151 (95.0) | 135 (91.8) | 140 (87.0) |
Tobacco cigarettes smoked per day | Â | 2, 4 | 1, 3 | 2, 4 | 1, 3 |
 0 cigarettes (former or never smoker) | 221 (34.7) | 50 (29.6) | 56 (35.2) | 41 (27.9) | 74 (46.0) |
 20 or fewer cigarettes per day | 364 (57.3) | 102 (60.3) | 98 (61.6) | 85 (57.9) | 79 (49.1) |
 21 or more cigarettes per day | 51 (8.0) | 17 (10.1) | 5 (3.1) | 21 (14.3) | 8 (5.0) |
TOBACCO PRODUCT USE, people with a history of use | N = 588 | n = 162 | n = 151 | n = 135 | n = 140 |
Age first started smoking | Â | 4 | . | . | 1 |
 < 14 | 58 (9.9) | 14 (8.6) | 20 (13.2) | 12 (8.9) | 12 (8.6) |
 14–15 | 140 (22.0) | 53 (32.7) | 29 (19.2) | 41 (30.4) | 17 (12.1) |
 16–17 years | 223 (35.1) | 57 (35.2) | 62 (41.1) | 57 (42.2) | 47 (33.6) |
 18–24 years | 125 (19.7) | 31 (19.1) | 35 (23.2) | 17 (12.6) | 58 (30.0) |
 25 years or older | 42 (7.1) | 7 (4.3) | 5 (3.3) | 8 (5.9) | 22 (15.7) |
Used both ENDS and at least one tobacco cigarette in the past 30 days |  | 3 | 3 | 1, 2 |  |
 No | 334 (56.8) | 100 (59.2) | 93 (61.6) | 62 (45.9) | 79 (56.4) |
 Yes | 254 (39.9) | 62 (36.7) | 58 (38.4) | 73 (54.1) | 61 (43.6) |
CIGARETTE USE, current smokers | N = 415 | n = 119 | n = 103 | n = 106 | n = 87 |
Number of minutes to first cigarettes | Â | 2 | 1, 3 | 2 | . |
 <  5 min | 64 (15.4) | 20 (16.8) | 11 (10.7) | 20 (18.9) | 13 (14.9) |
 6–30 min | 180 (43.4) | 57 (47.9) | 39 (37.9) | 46 (43.4) | 38 (43.7) |
 31–60 min | 62 (14.9) | 17 (14.3) | 10 (9.7) | 16 (15.1) | 19 (21.8) |
 > 60 min | 109 (26.3) | 25 (21.0) | 43 (41.7) | 24 (22.6) | 17 (19.5) |
Ever tried to quit smoking in the past | Â | 2, 3, 4 | 1 | 1 | 1 |
 Yes, was successful | 152 (36.6) | 35 (29.4) | 42 (40.8) | 35 (33.0) | 40 (46.0) |
 Yes, was not successful | 203 (48.9) | 74 (62.2) | 47 (45.6) | 50 (47.2) | 32 (36.8) |
 No | 60 (14.5) | 10 (8.4) | 14 (13.6) | 21 (19.8) | 15 (17.2) |