Table 2 Characteristics of smoking histories of lung cancer cases and controls
Men (N=1,630) | Women (N=1,075) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Model | Cigarette smoking variables | Unit or category | Cases | Controls | Cases | Controls | ||||||||
N (%) | Median value | N (%) | Median value | N (%) | Median value | N (%) | Median value | |||||||
a | Ever smoking | No | 18 | (2.5%) | - | 158 | (17.7%) | - | 32 | (6.9%) | - | 309 | (50.6%) | - |
Yes | 718 | (97.5%) | - | 736 | (82.3%) | - | 432 | (93.1%) | - | 302 | (49.4%) | - | ||
Among subjects who ever smoked | ||||||||||||||
b | Age of initiation | In years: Mean [SD] | 15.6 [3.4] | - | 16.8 [4.0] | - | 18.1 [5.4] | - | 20.1 [6.9] | - | ||||
c | Smoking status | Ex-smoker | 225 | (31.3%) | - | 478 | (64.9%) | - | 93 | (21.5%) | - | 170 | (56.3%) | - |
Current smoker | 493 | (68.9%) | - | 258 | (35.1%) | - | 339 | (78.5%) | - | 132 | (43.7%) | - | ||
d | Duration of smoking (in years)a | ]0-20] | 23 | (3.2%) | 15.0 | 141 | (19.2%) | 14.0 | 17 | (3.9%) | 10.0 | 90 | (29.8%) | 11.5 |
]20-30] | 62 | (8.6%) | 26.1 | 154 | (20.9%) | 26.5 | 65 | (15.1%) | 27.1 | 67 | (22.2%) | 26.0 | ||
]30-40] | 178 | (24.8%) | 36.0 | 175 | (23.8%) | 35.0 | 143 | (33.1%) | 35.6 | 80 | (26.5%) | 35.8 | ||
]40-50] | 267 | (37.2%) | 45.1 | 191 | (25.9%) | 45.3 | 143 | (33.1%) | 45.0 | 50 | (16.5%) | 44.9 | ||
>50 | 188 | (26.2%) | 53.0 | 75 | (10.2%) | 53.4 | 64 | (14.8%) | 52.8 | 15 | (5%) | 55.0 | ||
e | Intensity of smoking (cig/day) | ]0-20] | 86 | (12%) | 20.0 | 250 | (34%) | 15.0 | 115 | (26.6%) | 15.0 | 170 | (56.3%) | 10.0 |
]20-30] | 327 | (45.5%) | 25.0 | 279 | (37.9%) | 25.0 | 223 | (51.6%) | 25.0 | 95 | (31.4%) | 25.0 | ||
]30-40] | 91 | (12.7%) | 40.0 | 68 | (9.2%) | 39.5 | 47 | (10.9%) | 35.0 | 18 | (6%) | 37.0 | ||
]40-50] | 144 | (20.1%) | 50.0 | 101 | (13.7%) | 50.0 | 36 | (8.3%) | 50.0 | 15 | (5%) | 50.0 | ||
>50 | 70 | (9.7%) | 75.0 | 38 | (5.2%) | 75.0 | 11 | (2.6%) | 75.0 | 4 | (1.3%) | 62.5 | ||
f | Cumulative amount of smoking (in pack-years)a | ]0-20] | 24 | (3.3%) | 14.0 | 165 | (22.4%) | 10.0 | 28 | (6.5%) | 12.9 | 123 | (40.7%) | 7.1 |
]20-40] | 87 | (12.1%) | 33.7 | 169 | (23%) | 30.0 | 103 | (23.8%) | 32.5 | 95 | (31.4%) | 30.2 | ||
]40-60] | 204 | (28.4%) | 51.5 | 181 | (24.6%) | 49.4 | 178 | (41.2%) | 49.7 | 60 | (19.9%) | 49.7 | ||
]60-80] | 156 | (21.7%) | 65.9 | 111 | (15.1%) | 69.8 | 72 | (16.7%) | 66.3 | 12 | (4%) | 62.9 | ||
]80-100] | 64 | (8.9%) | 90.8 | 46 | (6.2%) | 89.7 | 21 | (4.9%) | 93.7 | 6 | (2%) | 92.5 | ||
>100 | 183 | (25.5%) | 127.2 | 64 | (8.7%) | 125.0 | 30 | (6.9%) | 119.7 | 6 | (2%) | 116.5 | ||
g | CSI indexa | ]0-1] | 33 | (4.6%) | 0.6 | 203 | (27.6%) | 0.6 | 16 | (3.7%) | 0.5 | 113 | (37.4%) | 0.5 |
]1-2] | 192 | (26.7%) | 1.7 | 309 | (42%) | 1.5 | 177 | (41%) | 1.7 | 129 | (42.7%) | 1.5 | ||
]2-2.5] | 288 | (40.1%) | 2.3 | 158 | (21.5%) | 2.2 | 200 | (46.3%) | 2.2 | 52 | (17.2%) | 2.2 | ||
]2.5-3] | 166 | (23.1%) | 2.7 | 55 | (7.5%) | 2.7 | 34 | (7.9%) | 2.7 | 8 | (2.7%) | 2.7 | ||
>3 | 39 | (5.4%) | 3.2 | 11 | (1.5%) | 3.2 | 5 | (1.2%) | 3.1 | 0 | (0%) | - | ||
h | Time since cessation (in years)a | 0b | 493 | (68.7%) | 0 | 258 | (35.1%) | 0 | 339 | (78.5%) | 0 | 132 | (43.7%) | 0 |
]0-5] | 60 | (8.3%) | 2.7 | 51 | (6.9%) | 2.8 | 35 | (8.1%) | 2.4 | 35 | (11.6%) | 2.1 | ||
]5-10] | 50 | (7%) | 8.3 | 67 | (9.1%) | 7.8 | 20 | (4.6%) | 6.8 | 32 | (10.6%) | 7.8 | ||
]10-15] | 41 | (5.7%) | 12.6 | 80 | (10.9%) | 12.8 | 20 | (4.6%) | 12.7 | 19 | (6.3%) | 12.1 | ||
]15-20] | 41 | (5.7%) | 17.4 | 92 | (12.5%) | 17.9 | 11 | (2.5%) | 16.4 | 25 | (8.3%) | 18.1 | ||
>20 | 33 | (4.6%) | 24.7 | 188 | (25.5%) | 28.0 | 7 | (1.6%) | 32.0 | 59 | (19.5%) | 24.8 | ||