Distributions of select characteristics by case-control status
Variable | Cases (n = 724) | Controls (n = 791) |
---|---|---|
Sex, (%) | ||
Male | 479 (66.2) | 519 (65.6) |
Female | 245 (33.8) | 272 (34.4) |
Mean age in years (SD) | 57.0 (10.2) | 56.6 (8.8) |
Smoking status (%) | ||
Never | 303 (41.9)a | 457 (57.8) |
Everb | 421 (58.1)a | 334 (42.2) |
<27 pack-years | 156 (37.1)a | 188 (56.3) |
≥27 pack-years | 265 (62.9)a | 146 (43.7) |
Mean pack-years smoked (SD) | 34.8 (23.0)a | 27.4 (16.3) |
Histological type (%) | ||
Squamous cell carcinoma | 263 (36.3) | |
Adenocarcinoma | 319 (44.1) | |
Otherc | 142 (19.6) |
a P < 0.0000, compared with controls.
b Includes 68 former smokers (26 cases and 42 controls).
c Other includes undifferentiated cancer (n = 60), bronchioalveolar carcinoma (n = 27), and small cell carcinoma (n = 55).