Table 1 Baseline sample characteristics

WAI, mean (SD)

38.1 (7.4)

39.5

34.0; 43.5

0.84

WAI

 Good or excellent, %

65.2

 Poor or moderate, %

34.8

Gender: female, %

33.8

Age, mean (SD)

51.1 (4.2)

51.0

47.0; 55.0

Low educational level, %

34.8

White-collar worker, %

97.4

Exercise: at least two hours per week, %

46.6

BMI ≥ 25, %

58.5

Smoking, %

21.4

Health-related behaviour (0–3), mean (SD)

1.7 (0.9)

2.0

1.0; 2.0

Physical demands (0–12), mean (SD)

1.3 (2.0)

1.0

0.0; 2.0

0.68

Psychological job demands (0–4), mean (SD)

1.5 (0.9)

1.4

0.8; 2.2

0.82

Job control (0–4), mean (SD)

3.2 (0.7)

3.3

2.8; 3.8

0.79

Effort (5–25), mean (SD)

14.9 (4.5)

15.0

12.0; 18.0

0.84

Reward (11–55), mean (SD)

43.8 (8.7)

45.0

37.0; 52.0

0.89

ER ratio, mean (SD)

0.8 (0.4)

0.7

0.5; 1.0

ERI: ER ratio > 1, %

25.9