Table 1.
General characteristics of subjects
| Characteristics | Cases n (%) | Controls n (%) |
|---|---|---|
| No. | 3938 | 1700 |
| Age(mean ± SD)* | 64.8 ± 9.6 | 52.2 ± 14.3 |
| ≤65 years | 1803 (45.8) | 1308 (76.9) |
| > 65 years | 2135 (54.2) | 392 (23.1) |
| Gender* | ||
| Male | 3128 (79.4) | 821 (48.3) |
| Female | 810 (20.6) | 879 (51.7) |
| Smoking status* | ||
| Never | 900 (22.8) | 1000 (58.8) |
| Ever | 2951 (74.9) | 655 (38.5) |
| unknown | 87 (2.2) | 45 (2.6) |
| Histological type | ||
| ADC | 1523 (38.7) | |
| SQC | 1519 (38.6) | |
| SCLC | 574 (14.6) | |
| Others | 322 (8.2) |
SD, standard deviation; ADC, adenocarcinoma; SQC, squamous cell carcinoma;
SCLC, small cell lung cancer; others, large cell carcinoma and mixed types; *, p < 0.01.