Table 1.
Characteristics of participant by the history and duration of night shift work.
| History and duration of night shift work | ||||
|---|---|---|---|---|
| Characteristics | Never (n = 2,876) | <5 years (n = 1,232) | ≥5 years (n = 3,303) | Ever (n = 4,535) |
| Study site | ||||
| Shiyan | 2,762 (96.0) | 1,081 (87.7) | 2,376 (71.9) | 3,457 (76.2) |
| Hengyang | 114 (4.0) | 151 (12.3) | 927 (28.1) | 1,078 (23.8) |
| Age (years) | 41.5 ± 9.1 | 39.5 ± 9.5 | 44.4 ± 6.6 | 43.1 ± 7.8 |
| Male | 1,976 (68.7) | 984 (79.9) | 2,593 (78.5) | 3,577 (78.9) |
| Han ethnicity | 2,823 (98.2) | 1,217 (98.8) | 3,264 (98.8) | 4,481 (98.8) |
| Marital status | ||||
| Unmarried | 345 (12.0) | 222 (18.0) | 133 (4.0) | 355 (7.8) |
| Married or live together | 2,440 (84.9) | 960 (77.9) | 3,012 (91.2) | 3,972 (87.6) |
| Widowed | 15 (0.5) | 7 (0.6) | 21 (0.6) | 28 (0.6) |
| Divorced | 76 (2.6) | 43 (3.5) | 137 (4.2) | 180 (4.0) |
| Annual family income (CNY) | ||||
| <30,000 | 122 (4.3) | 94 (7.6) | 477 (14.4) | 571 (12.6) |
| 30,000–49,999 | 532 (18.5) | 359 (29.1) | 1,222 (37.0) | 1,581 (34.8) |
| 50,000–99,999 | 1,324 (46.0) | 570 (46.3) | 1,343 (40.7) | 1,913 (42.2) |
| ≥100,000 | 898 (31.2) | 209 (17.0) | 261 (7.9) | 470 (10.4) |
| Educational level | ||||
| Middle school and below | 101 (3.5) | 79 (6.4) | 468 (14.2) | 547 (12.1) |
| High school | 778 (27.1) | 497 (40.3) | 1,900 (57.5) | 2,397 (52.8) |
| College and above | 1,997 (69.4) | 656 (53.3) | 935 (28.3) | 1,591 (35.1) |
| Smoking | ||||
| Never | 2,000 (69.6) | 722 (58.6) | 1,656 (50.1) | 2,378 (52.4) |
| Past | 145 (5.0) | 97 (7.9) | 337 (10.2) | 434 (9.6) |
| Current | 731 (25.4) | 413 (33.5) | 1,310 (39.7) | 1,723 (38.0) |
| Passive smoke exposure | 1,641 (57.1) | 785 (63.7) | 2,028 (61.4) | 2,813 (62.0) |
| Alcohol drinking | ||||
| Never | 1,828 (63.5) | 724 (58.8) | 1,986 (60.1) | 2,710 (59.8) |
| Past | 62 (2.2) | 53 (4.3) | 138 (4.2) | 191 (4.2) |
| Current | 986 (34.3) | 455 (36.9) | 1,179 (35.7) | 1,634 (36.0) |
| BMI (kg/m2) | 24.0 ± 2.7 | 24.1 ± 2.9 | 24.2 ± 2.8 | 24.1 ± 2.8 |
| Sleep disturbance (PSQI >5) | 898 (31.2) | 443 (36.0) | 1,365 (41.3) | 1,808 (39.9) |
| Daytime sleepiness (ESS >10) | 918 (31.9) | 426 (34.6) | 1,013 (30.7) | 1,439 (31.7) |
| Anxiety (GAD-2 ≥3) | 166 (5.8) | 77 (6.3) | 214 (6.5) | 291 (6.4) |
| Depression (PHQ-2 ≥3) | 171 (6.0) | 89 (7.2) | 285 (8.6) | 374 (8.3) |
CNY, Chinese yuan; BMI, body mass index; PSQI, Pittsburgh Sleep Quality Index; ESS, Epworth Sleepiness Scale; GAD-2, 2-item Generalized Anxiety Disorder; PHQ-2:2-item, Patient Health Questionnaire.