Table 2 Association between general characteristics and night work
Night work | p value* | ||||
|---|---|---|---|---|---|
Yes (N = 3712) | No (N = 25999) | ||||
N | % | N | % | ||
Sex | |||||
Male | 2872 | 77.4 | 14474 | 55.7 | <.0001 |
Female | 840 | 22.6 | 11525 | 44.3 | |
Age (years) | |||||
<30 | 596 | 16.1 | 4308 | 16.6 | <.0001 |
30-39 | 1025 | 27.6 | 7894 | 30.4 | |
40-49 | 941 | 25.4 | 7593 | 29.2 | |
50-59 | 669 | 18.0 | 4350 | 16.7 | |
≥60 | 481 | 13.0 | 1854 | 7.1 | |
Level of education completed | |||||
Middle school or below | 492 | 13.3 | 2828 | 10.9 | <.0001 |
High school | 1683 | 45.3 | 9917 | 38.1 | |
College or above | 1537 | 41.4 | 13254 | 51.0 | |
Monthly income (Korean won) | |||||
<1,000,000 | 364 | 9.8 | 3416 | 13.1 | <.0001 |
1,000,000 – 2,000,000 | 1421 | 38.3 | 10404 | 40.0 | |
2,000,000 – 3,000,000 | 1070 | 28.8 | 6988 | 26.9 | |
≥3,000,000 | 857 | 23.1 | 5184 | 19.9 | |
Smoking | |||||
Non-smoker | 1460 | 39.3 | 14858 | 57.2 | <.0001 |
Ex-smoker | 608 | 16.4 | 2658 | 10.2 | |
Current smoker | 1644 | 44.3 | 8483 | 32.6 | |
Alcohol drinking frequency (drinks) | |||||
None | 677 | 18.2 | 6247 | 24.0 | <.0001 |
≤1 per week | 1179 | 31.8 | 6455 | 24.8 | |
≥2 per week | 1856 | 50.0 | 13297 | 51.1 | |
Job type | |||||
White collar | 1023 | 27.6 | 11126 | 42.8 | <.0001 |
Service | 758 | 20.4 | 6069 | 23.3 | |
Blue collar | 1931 | 52.0 | 8804 | 33.9 | |
Company size (no. of employees) | |||||
<5 | 627 | 17.4 | 6964 | 27.6 | <.0001 |
5-49 | 1634 | 45.3 | 12844 | 50.9 | |
50-299 | 822 | 22.8 | 3902 | 15.5 | |
≥300 | 523 | 14.5 | 1529 | 6.1 | |
Years of service | |||||
<1 | 539 | 14.5 | 3980 | 15.3 | 0.0004 |
1-9 | 2190 | 59.0 | 15901 | 61.2 | |
≥10 | 983 | 26.5 | 6118 | 23.5 | |
Shift work | |||||
No | 1833 | 49.4 | 25039 | 96.3 | <.0001 |
Yes | 1879 | 50.6 | 960 | 3.7 | |
Working time (hours/week) | |||||
<40 | 197 | 5.3 | 2773 | 10.7 | <.0001 |
40-48 | 1377 | 37.1 | 14144 | 54.4 | |
49-60 | 1216 | 32.8 | 7355 | 28.3 | |
≥61 | 922 | 24.8 | 1727 | 6.6 | |
Hypertension | |||||
No | 3457 | 93.1 | 24791 | 95.4 | <.0001 |
Yes | 255 | 6.9 | 1208 | 4.6 | |
Obesity | |||||
No | 3607 | 97.2 | 25551 | 98.3 | <.0001 |
Yes | 105 | 2.8 | 448 | 1.7 | |
Cardiovascular diseases | |||||
No | 3647 | 98.2 | 25729 | 99.0 | <.0001 |
Yes | 65 | 1.8 | 270 | 1.0 | |