Table 2 Demographic and occupational characteristics of the subjects according to work schedule
|  | Day time (06 am-06 pm) | Evening time (02 pm-12 am) | Fixed overnight (09 pm-08 am) | Night included regular rotation | p-value | ||||
|---|---|---|---|---|---|---|---|---|---|
N | % (SE) | N | % (SE) | N | % (SE) | N | % (SE) | Â | |
Age (yr, mean (SD)) | 43.9 (0.2) | 39.8 (0.6) | 40.3 (0.8) | 41.2 (0.6) | <0.01 | ||||
Job category | |||||||||
 Office work | 1826 | 44.6 (0.8) | 139 | 38.8 (2.6) | 31 | 16.0 (2.6) | 40 | 16.0 (2.6) | <0.01 |
 Service and sales work | 596 | 14.6 (0.6) | 126 | 35.2 (2.5) | 48 | 24.7 (3.1) | 54 | 21.6 (3.1) |  |
 Manual work | 1668 | 40.8 (0.8) | 93 | 26.0 (2.3) | 115 | 59.3 (3.5) | 156 | 62.4 (3.5) |  |
Type of employment | |||||||||
 Permanent | 2177 | 52.8 (0.8) | 75 | 20.8 (2.1) | 115 | 58.7 (3.5) | 236 | 94.0 (1.5) | <0.01 |
 Temporary | 201 | 4.9 (0.3) | 63 | 17.5 (2.0) | 25 | 12.7 (2.4) | 8 | 3.2 (1.1) |  |
 Daily workers | 226 | 5.5 (0.4) | 9 | 2.5 (0.8) | 9 | 4.6 (1.5) | 2 | 0.8 (0.6) |  |
 aOthers | 1515 | 36.8 (0.8) | 214 | 59.3 (2.6) | 47 | 24.0 (3.1) | 5 | 2.0 (0.9) |  |
Work hour | |||||||||
 40 h per week or less | 1544 | 37.5 (0.8) | 192 | 53.2 (2.6) | 127 | 64.8 (3.4) | 75 | 29.9 (2.9) | <0.01 |
 More than 40 h per week | 2575 | 62.5 (0.8) | 169 | 46.8 (2.6) | 69 | 35.2 (3.4) | 176 | 70.1 (2.9) |  |
Educational level | |||||||||
 Middle school or less | 656 | 15.9 (0.6) | 46 | 12.7 (1.8) | 27 | 13.8 (2.5) | 20 | 8.0 (1.7) | <0.01 |
 High school | 1510 | 36.7 (0.8) | 151 | 41.8 (2.6) | 120 | 61.2 (3.5) | 145 | 57.7 (3.1) |  |
 University or more | 1953 | 47.4 (0.8) | 164 | 45.4 (2.6) | 49 | 25.0 (3.1) | 86 | 34.3 (3.0) |  |
Home income quartile | |||||||||
 Low | 226 | 5.5 (0.4) | 25 | 7.0 (1.4) | 14 | 7.2 (1.8) | 7 | 2.8 (1.0) | 0.12 |
 Medium low | 944 | 23.1 (0.7) | 80 | 22.4 (2.2) | 39 | 20.0 (2.9) | 52 | 20.8 (2.6) |  |
 Medium high | 1383 | 33.8 (0.7) | 121 | 33.9 (2.5) | 76 | 39.0 (3.5) | 105 | 42.0 (3.1) |  |
 High | 1535 | 37.6 (0.8) | 131 | 36.7 (2.6) | 66 | 33.8 (3.4) | 86 | 34.4 (3.0) |  |
Marriage status | |||||||||
 Positive | 3407 | 82.7 (0.6) | 241 | 66.6 (2.5) | 134 | 68.4 (3.3) | 199 | 79.3 (2.6) | <0.01 |
 Negative | 712 | 17.3 (0.6) | 120 | 33.6 (2.5) | 62 | 31.6 (3.3) | 52 | 20.7 (2.6) |  |
Perceived stress | |||||||||
 Low | 2869 | 69.7 (0.7) | 244 | 67.6 (2.5) | 145 | 74.0 (3.1) | 183 | 72.9 (2.8) | 0.30 |
 High | 1250 | 30.3 (0.7) | 117 | 32.4 (2.5) | 51 | 26.0 (3.1) | 68 | 27.1 (2.8) |  |