Table 1. General characteristics and prevalence mental health outcome of study population.
| Working schedule | p-value | |||
|---|---|---|---|---|
| Daytime work | Shiftwork | |||
| n (%) | n (%) | |||
| N | 5635 (40.0) | 8469 (60.0) | ||
| Gender | ||||
| Male | 7243 (51.7) | 4395 (78.2) | 2848 (33.9) | <0.0001 |
| Female | 6776 (48.3) | 1226 (21.8) | 5550 (66.1) | |
| Age group | ||||
| <30 | 4688 (33.2) | 1146 (20.3) | 3542 (41.8) | <0.0001 |
| 30-<40 | 6897 (48.9) | 2708 (48.1) | 4189 (49.5) | |
| 40-<50 | 2315 (16.4) | 1587 (28.2) | 728 (8.6) | |
| ≥50 | 204 (1.0) | 194 (3.4) | 10 (0.1) | |
| Workplace | ||||
| Factory A | 8568 (61.2) | 4001 (71.6) | 4567 (54.2) | <0.0001 |
| Factory B | 5398 (38.5) | 1548 (27.7) | 3850 (45.7) | |
| Others | 40 (0.3) | 36 (0.6) | 4 (0.1) | |
| Educational level | ||||
| High school or less | 4749 (33.7) | 573 (10.2) | 4176 (49.4) | <0.0001 |
| Junior college | 4629 (32.9) | 910 (16.2) | 3719 (44.0) | |
| College | 3609 (25.6) | 3080 (85.4) | 529 (6.3) | |
| Graduate school | 1093 (7.8) | 1061 (18.9) | 32 (0.4) | |
| Marital status | ||||
| Unmarried | 6323 (44.8) | 2016 (35.8) | 4307 (50.9) | <0.0001 |
| Married | 7567 (53.7) | 3563 (63.2) | 4004 (47.3) | |
| Others | 214 (1.5) | 56 (1.0) | 158 (1.9) | |
| BMI (kg/m2) | ||||
| <25 | 10678 (75.7) | 3912 (69.4) | 6566 (79.9) | <0.0001 |
| 25-<30 | 2939 (20.8) | 1523 (27.3) | 1393 (16.5) | |
| ≥30 | 487 (3.5) | 185 (3.28) | 302 (3.6) | |
| Insomnia | ||||
| Absence | 7559 (55.1) | 3823 (69.8) | 37.36 (45.3) | <0.0001 |
| Sub-threshold | 4305 (31.4) | 1289 (29.8) | 3016 (36.6) | |
| Moderate | 1529 (11.1) | 303 (5.5) | 1226 (14.9) | |
| Severe | 330 (2.4) | 61 (1.1) | 269 (3.3) | |
| Depression* | ||||
| No | 11972(85.80) | 5122(91.91) | 6850(81.74) | <0.0001 |
| Yes | 1981(14.20) | 451(8.09) | 1530(18.26) | |
| Suicidal ideation | ||||
| No | 13752 (97.2) | 5582 (98.6) | 8170 (96.2) | <0.0001 |
| Yes | 401 (2.8) | 77 (1.4) | 324 (3.8) | |
* Total score of 4-item CES-D is 4 or more