Table 1.
Baseline characteristics of the study population stratified according to age, sex, smoking status, and income
| Characteristics | Total
|
Male
|
Female
|
|---|---|---|---|
| n (%) | n (%) | n (%) | |
| Age (n=6,517) | |||
| 40–49 | 3,334 (51.2) | 1,686 (56.2) | 1,648 (46.8) |
| 50–59 | 1,733 (26.6) | 775 (25.9) | 958 (27.2) |
| 60–69 | 1,450 (22.2) | 536 (17.9) | 914 (26.0) |
| Sex (n=6,517) | |||
| Male | 2,997 (46.0) | – | – |
| Female | 3,520 (54.0) | – | – |
| Smoking history (n=6,517) | |||
| Never smokers | 4,018 (61.7) | 643 (21.5) | 3,375 (95.9) |
| Former smokers | 1,005 (15.4) | 965 (32.2) | 40 (1.1) |
| Current smokers | 1,494 (22.9) | 1,389 (46.3) | 105 (3.0) |
| Income (n=6,514) | |||
| First quartile | 2,064 (31.6) | 657 (21.9) | 1,409 (40.0) |
| Second quartile | 1,941 (29.8) | 928 (31.0) | 1,013 (28.8) |
| Third quartile | 1,972 (30.2) | 1,087 (36.3) | 886 (25.2) |
| Fourth quartile | 537 (8.2) | 325 (10.8) | 212 (6.0) |
| Education (n=6,485) | |||
| Elementary school or lower | 1,963 (30.3) | 464 (15.5) | 1,499 (42.9) |
| Middle school | 1,440 (22.2) | 611 (20.5) | 829 (23.7) |
| High school | 2,118 (32.7) | 1,168 (39.1) | 950 (27.1) |
| College/university or higher | 964 (14.9) | 744 (24.9) | 220 (6.3) |