Characteristics of the study population
Variables | Case-control study | P | |
---|---|---|---|
Cases (n = 720) | Controls (n = 720) | ||
Age (y) | |||
Mean ± SD | 61.3 ± 8.8 | 60.6 ± 9.3 | 0.12* |
Median (interquartile) | 62 (12) | 61 (12) | 0.06† |
Sex | |||
Male | 565 (78.5)‡ | 565 (78.5) | |
Female | 155 (21.5) | 155 (21.5) | |
Smoking status | <0.001§ | ||
Current | 463 (64.3) | 331 (46.0) | |
Former | 116 (16.1) | 191 (26.5) | |
Never | 141 (19.6) | 198 (27.5) | |
Pack-years∥ | |||
Mean ± SD | 39.8 ± 18.1 | 32.8 ± 18.0 | <0.001* |
Median (interquartile) | 40 (20) | 31 (23) | <0.001† |
Histologic types | |||
Squamous cell carcinoma | 320 (44.4) | ||
Adenocarcinoma | 273 (37.9) | ||
Large cell carcinoma | 12 (1.7) | ||
Small cell carcinoma | 115 (16.0) |