Table 1. General characteristics of study subjects.
| Characteristics | All subjects | PSM subjects | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Hg < 5.8 µg/L (n = 4,438) | Hg ≥ 5.8 µg/L (n = 1,737) | χ2 or t-value | p-value | Hg < 5.8 µg/L (n = 3,275) | Hg ≥ 5.8 µg/L (n = 1,833) | χ2 or t-value | p-value | ||
| Sex | 156.599 | 0.000 | 0.303 | 0.582 | |||||
| Male | 1,560 (35.2) | 912 (52.5) | 1,165 (26.3) | 595 (34.3) | |||||
| Female | 2,878 (64.8) | 825 (47.5) | 1,665 (37.5) | 820 (47.2) | |||||
| Age (years) | 66.1 ± 12.23 | 63.68 ± 11.33 | 7.151 | 0.000 | 65.24 ± 12.21 | 65.35 ± 10.90 | 0.300 | 0.764 | |
| Smoking | 26.980 | 0.000 | 1.144 | 0.564 | |||||
| Current | 576 (13.0) | 258 (14.9) | 409 (9.2) | 212 (12.2) | |||||
| Ex | 676 (15.2) | 345 (19.9) | 431 (9.7) | 230 (13.2) | |||||
| Non | 3,186 (71.8) | 1,134 (65.3) | 1,990 (44.8) | 973 (56.0) | |||||
| Alcohol drink | 99.763 | 0.000 | 0.229 | 0.632 | |||||
| 1 | 1,731 (39.1) | 923 (53.1) | 1,298 (29.2) | 638 (36.7) | |||||
| 0 | 2,701 (60.9) | 814 (46.9) | 1,532 (34.5) | 777 (44.7) | |||||
| Income | 38.340 | 0.000 | 0.971 | 0.808 | |||||
| 1 | 2,685 (60.5) | 921 (53.0) | 1,732 (39.0) | 847 (48.8) | |||||
| 2 | 809 (18.2) | 350 (20.1) | 502 (11.3) | 255 (14.7) | |||||
| 3 | 593 (13.4) | 260 (15.0) | 381 (8.6) | 196 (11.3) | |||||
| 4 | 351 (7.9) | 206 (11.9) | 215 (4.8) | 117 (6.7) | |||||
Values are presented as number (%). Alcohol drink: 1 - person who had lifetime drinking experience, 0 - never drink; Income: quartile subgroup for gross house income.
PSM: propensity score matching.