Table 1.
Characteristics of social-demographics and major risk factors of NPC cases and controls (%)
| Variables | Cases (n = 1845) | Controls (n = 2275) | P* |
|---|---|---|---|
| Age, years | 46.11 ± 10.99 | 46.42 ± 11.74 | 0.387 |
| Sex | |||
| Female | 496 (26.88) | 665 (29.23) | |
| Male | 1373 (73.12) | 1610 (70.77) | 0.096 |
| Education | |||
| High school or lower | 1558 (84.77) | 1554 (68.52) | |
| College or above | 280 (15.23) | 714 (31.48) | <0.001 |
| Living type | |||
| Block | 671 (37.68) | 1070 (47.79) | |
| Bungalow | 1110 (62.32) | 1169 (52.21) | < 0.001 |
| Cigarette smoking, pack-years | |||
| Never-smoker | 839 (45.75) | 1190 (52.56) | |
| <20 | 406 (22.42) | 406 (25.93) | |
| ≥20 | 566 (31.25) | 487 (21.52) | < 0.001 |
| Tea | |||
| Less than monthly | 653 (35.96) | 495 (21.80) | |
| Monthly | 312 (17.18) | 634 (27.92) | |
| Weekly or more | 851 (46.86) | 1142 (50.29) | < 0.001 |
| Herbal tea | |||
| Less than monthly | 474 (25.85) | 427 (18.96) | |
| Monthly | 725 (39.53) | 984 (43.69) | |
| Weekly or more | 635 (34.62) | 841 (37.34) | < 0.001 |
| Slow-cooked soup | |||
| Less than monthly | 264 (14.43) | 80 (3.55) | |
| Monthly | 207 (11.32) | 232 (10.30) | |
| Weekly or more | 1358 (74.25) | 1940 (86.15) | < 0.001 |
| Salted fish | |||
| Less than monthly | 1472 (80.22) | 2014 (89.15) | |
| Monthly | 203 (11.06) | 122 (5.40) | |
| Weekly or more | 160 (8.72) | 123 (5.44) | < 0.001 |
| Preserved vegetables | |||
| Less than monthly | 1318 (71.67) | 1961 (86.81) | |
| Monthly | 280 (15.23) | 149 (6.60) | |
| Weekly or more | 241 (13.10) | 149 (6.60) | < 0.001 |
| Family history of NPC | |||
| No | 1537 (83.49) | 2075 (94.71) | |
| Yes | 304 (16.51) | 116 (5.29) | < 0.001 |
*T-tests and Chi-Square tests were used to describe certain characteristics between cases and controls