Skip to main content

Table 1 Subjects’ characteristics, insomnia symptoms and work productivity

From: The relationship between insomnia symptoms and work productivity among blue-collar and white-collar Japanese workers engaged in construction/civil engineering work: a cross-sectional study

  

Total (n = 17,828)

Blue-collar (n = 7292)

White-collar (n = 10,536)

p-value

Age

(y)

52.5 ± 7.6

51.6 ± 7.8

53.2 ± 7.4

< 0.001**

Sex

 Male

n (%)

15,837 (88.8)

7175 (98.4)

8662 (82.2)

< 0.001**

 Female

n (%)

1991 (11.2)

117 (1.6)

1874 (17.8)

Living alone

 No

n (%)

4133 (23.2)

5181 (71.1)

8514 (80.8)

< 0.001**

 Yes

n (%)

13,695 (76.8)

2111 (28.9)

2022 (19.2)

Working pattern

 Daytime worker

n (%)

16,711 (93.7)

6452 (88.5)

10,259 (97.4)

< 0.001**

 Shift worker

n (%)

834 (4.7)

795 (10.9)

39 (0.4)

Working time

 40-60 h

n (%)

12,470 (69.9)

4861 (66.7)

7609 (72.2)

< 0.001**

 < 40 h

n (%)

3068 (17.2)

783 (10.7)

2285 (21.7)

 ≥ 60 h

n (%)

2290 (12.8)

1648 (22.6)

642 (6.1)

Working days

(day/week)

5.2 ± 0.5

5.5 ± 0.6

5.1 ± 0.3

< 0.001**

Physical health

 Good/average

n (%)

15,603 (87.5)

6371 (87.4)

9232 (87.6)

0.631

 Poor

n (%)

2225 (12.5)

921 (12.6)

1304 (12.4)

Mental health

 Good/average

n (%)

15,807 (88.7)

6393 (87.7)

9414 (89.4)

< 0.01*

 Poor

n (%)

2021 (11.3)

899 (12.3)

1122 (10.6)

Sleep duration

 7-8 h

n (%)

4179 (23.4)

795 (24.2)

2415 (22.9)

< 0.001**

 < 7 h

n (%)

12,385 (69.5)

4884 (67.0)

7501 (71.2)

 ≥ 8 h

n (%)

1264 (7.1)

644 (8.8)

620 (5.9)

Insomnia symptoms

 DIS

n (%)

1410 (7.9)

568 (7.8)

842 (8.0)

0.643

 DMS

n (%)

2914 (16.3)

1166 (16.0)

1748 (16.6)

0.296

 EMA

n (%)

2335 (13.1)

928 (12.7)

1407 (13.4)

0.230

Work performance

 90–100%

n (%)

8999 (50.5)

3198 (43.9)

5801 (55.1)

< 0.001**

 <  90%

n (%)

8829 (49.5)

4094 (56.1)

4735 (44.9)

Absence

 None

n (%)

16,163 (90.7)

6690 (91.7)

9473 (89.9)

< 0.001**

 ≥ 1 day

n (%)

1665 (9.3)

602 (8.3)

1063 (10.1)

  1. Values are expressed as mean ± standard deviation for continuous variables
  2. DIS Difficulty initiating sleep, DMS Difficulty maintaining sleep, EMA Early morning awakening
  3. * < 0.05, ** < 0.001