Table 2

Associations between depressive symptoms and the studied variables in the previous one month

Men

Women

Without depressive symptoms

With depressive symptoms

Without depressive symptoms

With depressive symptoms

n = 2773

(%)

n = 252

(%)

n = 749

(%)

n = 88

(%)

The number of days of off-duty per month

None

256

(85.6)

43

(14.4)

54

(77.1)

16

(22.9)

1-4 days

1088

(90.4)

115

(9.6)

253

(90.7)

26

(9.3)

5-7 days

915

(92.8)

71

(7.2)

201

(90.5)

21

(9.5)

8 days or more

514

(95.7)

23

(4.3)

241

(90.6)

25

(9.4)

The number of days of on-call per month

None

1260

(94.2)

78

(5.8)

445

(93.5)

31

(6.5)

1-4 days

615

(91.9)

54

(8.1)

130

(87.2)

19

(12.8)

5-7 days

338

(89.2)

41

(10.8)

50

(84.7)

9

(15.3)

8 days or more

560

(87.6)

79

(12.4)

124

(81.0)

29

(19.0)

Average sleeping hours for days not working overnight

Less than 5 hours

216

(82.1)

47

(17.9)

65

(78.3)

18

(21.7)

5 to less than 6 hours

892

(91.3)

85

(8.7)

256

(88.3)

34

(11.7)

6 to less than 7 hours

1300

(93.5)

90

(6.5)

338

(92.3)

28

(7.7)

7 hours or more

365

(92.4)

30

(7.6)

90

(91.8)

8

(8.2)

The number of days of overnight work per month

None

1178

(93.4)

83

(6.6)

440

(91.7)

40

(8.3)

Once

264

(91.7)

24

(8.3)

53

(89.8)

6

(10.2)

2 to 3 times

540

(90.3)

58

(9.7)

115

(84.6)

21

(15.4)

4 to 5 times

482

(91.1)

47

(8.9)

87

(89.7)

10

(10.3)

6 times or more

309

(88.5)

40

(11.5)

54

(83.1)

11

(16.9)

Wada et al. BMC Public Health 2010 10:127   doi:10.1186/1471-2458-10-127