Table 1

Baseline characteristics of the study sample

CharacteristicNumber (%) of participants (n=30 700)Self-assessed worktime control, mean (SE)Co-worker assessed worktime control, mean (SE)Incidence of disability pension per 1000 person-years (n=1178)
Sexp<0.0001p=0.003p=0.37
 Men6893 (22)2.67 (0.01)2.56 (0.01)8.72
 Women23807 (78)2.56 (0.01)2.59 (0.01)9.22
Socioeconomic positionp<0.0001p<0.0001p<0.0001
 Upper non-manual10462 (34)2.62 (0.01)2.50 (0.01)4.56
 Lower non-manual13863 (45)2.69 (0.01)2.72 (0.00)8.83
 Manual6375 (21)2.30 (0.01)2.41 (0.01)16.03
Shift workp<0.0001p<0.0001p<0.0001
 No22809 (75)2.63 (0.01)2.60 (0.00)8.03
 Evening4832 (16)2.55 (0.01)2.60 (0.01)11.90
 Night2888 (9)2.33 (0.02)2.43 (0.01)9.90
High job strainp<0.0001p<0.0001p<0.0001
 No22816 (75)2.70 (0.01)2.60 (0.00)7.05
 Yes7612 (25)2.25 (0.01)2.52 (0.01)13.92
Effort–reward imbalancep<0.0001p=0.022p<0.0001
 Low9313 (31)2.75 (0.01)2.59 (0.01)7.10
 Intermediate11217 (37)2.62 (0.01)2.58 (0.01)8.09
 High9844 (32)2.40 (0.01)2.57 (0.01)11.10
Current smokerp<0.0001p<0.0001p=0.003
 No23981 (81)2.57 (0.01)2.57 (0.00)8.42
 Yes5804 (19)2.64 (0.01)2.61 (0.01)10.41
Heavy drinker*p<0.0001p=0.20p=0.26
 No27606 (90)2.57 (0.01)2.58 (0.00)8.94
 Yes2932 (10)2.70 (0.02)2.59 (0.01)7.93
Physically inactivep=0.0004p=0.40p<0.0001
 No22568 (74)2.60 (0.01)2.58 (0.00)7.26
 Yes7833 (26)2.56 (0.01)2.58 (0.01)13.39
Obese (BMI≥30 kg/m2)p=0.58p=0.50p<0.0001
 No26407 (88)2.58 (0.01)2.58 (0.00)7.55
 Yes3617 (12)2.59 (0.01)2.59 (0.01)18.20
Psychological distressp<0.0001p=0.001p<0.0001
 No22285 (73)2.62 (0.01)2.58 (0.00)6.76
 Yes8284 (27)2.51 (0.01)2.60 (0.01)14.55
Suboptimal self-rated healthp<0.0001p=0.82p<0.0001
 No21496 (71)2.65 (0.01)2.58 (0.00)3.37
 Yes8807 (29)2.42 (0.01)2.58 (0.01)22.77
Prescribed antidepressantsp=0.02p<0.0001p<0.0001
 No29544 (96)2.58 (0.01)2.58 (0.00)7.90
 Yes1156 (4)2.65 (0.03)2.68 (0.02)32.99
Prescribed analgesicsp=0.0002p=0.009p<0.0001
 No27923 (91)2.59 (0.01)2.58 (0.00)7.43
 Yes2777 (9)2.53 (0.02)2.61 (0.01)22.83
Somatic illness§p=0.03p=0.006p<0.0001
 No26676 (87)2.59 (0.01)2.58 (0.00)6.66
 Yes4024 (13)2.56 (0.01)2.60 (0.01)24.37
Mental disorderp=0.09p<0.0001p<0.0001
 No26552 (86)2.59 (0.01)2.57 (0.00)6.75
 Yes4148 (14)2.56 (0.01)2.63 (0.01)22.65
Sickness absencep<0.0001p=0.007p<0.0001
 No25351 (83)2.61 (0.01)2.59 (0.00)4.84
 Yes5349 (17)2.46 (0.01)2.56 (0.01)29.00
  • Figures are numbers (percentages) unless otherwise stated. p Values of the differences by sample characteristics are derived from analysis of variance for worktime control and Cox proportional hazard models for disability retirement.

  • * Average weekly consumption ≥190 g of absolute alcohol for women and >275 g for men represents heavy drinking.

  • Leisure time physical activity <2 metabolic equivalent task h/day represents physically inactivity.

  • Individuals scoring ≥4 using the 12-item version of the General Health Questionnaire are classified as psychologically distressed.

  • § Diabetes, asthma or chronic obstructive bronchitis, hypertension, coronary heart disease, rheumatoid arthritis, cancer.