Table 1.

Baseline characteristics of the study population and subjects who developed lung cancer

Baseline characteristicAll subjects (N = 454,272; PY = 3,142,451), n (%)Subjects who developed lung cancer
P*
Squamous cell (N = 469; PY = 1,979), n (%)Adenocarcinoma (N = 465; PY = 1,954), n (%)Small cell (N = 214; PY = 940), n (%)Other (N = 209; PY = 899), n (%)
Age (y)
    40-49256,999 (56.6)92 (19.6)119 (25.6)46 (21.5)38 (18.2)0.17
    50-59166,829 (26.7)279 (59.5)247 (53.1)129 (60.3)123 (58.8)
    ≥6030,444 (6.7)98 (20.9)99 (21.3)39 (18.2)48 (23.0)
Job
    White collar100,652 (22.2)88 (18.8)98 (21.1)34 (15.9)48 (23.0)0.94
    Blue collar353,620 (77.8)381 (81.2)367 (78.9)180 (84.1)161 (77.0)
Place of residence
    City210,613 (46.3)200 (42.6)227 (48.8)93 (43.4)105 (50.2)0.77
    Town158,498 (34.9)148 (31.6)144 (31.0)74 (34.6)67 (32.1)
    Country85,161 (18.8)121 (25.8)94 (20.2)47 (22.0)37 (17.7)
Smoking status
    Never99,477 (22.7)16 (3.6)69 (15.4)4 (1.9)21 (10.3)0.003
    Former110,293 (25.2)59 (13.1)92 (20.5)30 (14.5)47 (22.9)
    Current228,206 (52.1)376 (83.3)288 (64.1)173 (83.6)137 (66.8)
Years of current smoking
    <1015,732 (7.1)12 (3.3)10 (3.7)4 (2.4)5 (3.8)0.75
    10-2055,658 (25.3)38 (10.6)32 (11.8)15 (8.9)17 (12.8)
    20-30100,524 (45.7)121 (33.6)95 (35.1)68 (40.5)41 (30.8)
    ≥3048,296 (21.9)189 (52.5)134 (49.4)81 (48.2)70 (52.6)
Amount of current smoking
    <1037,486 (16.5)28 (7.5)34 (11.8)16 (9.3)14 (10.3)0.64
    10-20186,043 (81.8)332 (89.0)246 (85.4)152 (87.7)118 (86.8)
    ≥203,798 (1.7)13 (3.5)8 (2.8)5 (3.0)4 (2.9)
Alcohol consumption (g/wk)
    067,578 (15.3)77 (17.2)85 (18.9)36 (17.2)33 (16.6)0.10
    <51.879,820 (18.0)68 (15.2)91 (20.2)32 (15.3)32 (16.1)
    51.8-124.2118,707 (26.8)103 (23.0)106 (23.5)50 (23.9)44 (22.1)
    124.2-289.8130,841 (29.5)148 (33.1)118 (26.1)61 (29.2)70 (35.1)
    ≥289.846,040 (10.4)51 (11.5)51 (11.3)30 (14.4)20 (10.1)
Leisure-time physical activity
    Low261,386 (58.7)289 (64.6)275 (61.2)140 (67.3)134 (66.0)0.36
    Moderate150,754 (33.8)119 (26.6)150 (33.4)51 (24.5)57 (28.1)
    High33,584 (7.5)39 (8.8)24 (5.4)17 (8.2)12 (5.9)
BMI (kg/m2)
    <25312,549 (68.8)357 (76.1)342 (73.5)156 (72.9)160 (76.5)0.72
    25-30323,503 (29.9)105 (22.4)116 (25.0)56 (26.2)44 (21.1)
    ≥3029,435 (1.3)7 (1.5)7 (1.5)2 (0.9)5 (2.4)
Diet preference
    Vegetables94,982 (21.2)86 (19.0)101 (22.0)41 (19.4)50 (24.4)0.50
    Mixed323,503 (72.2)327 (72.4)323 (70.4)154 (73.0)143 (69.7)
    Meats29,435 (6.6)39 (8.6)35 (7.6)16 (7.6)12 (5.9)
  • Abbreviations: PY, person-years; BMI, body mass index.

  • * Comparison among four lung cancer subgroups using Mantel-Haenszel χ2 test.

  • Number of cigarettes per day.