Table 3 Association between cumulative exposure to active job and cognitive functions at phases 5 and 7 (means and 95% CI)
Active job phases 1, 2 and 3MemoryInductive reasoning (AH4)Verbal meaning (Mill Hill)Phonemic fluencySemantic fluency
Model 1*Model 2†Model 1Model 2Model 1Model 2Model 1Model 2Model 1Model 2
Outcomes measured at phase 5
No exposure6.8 (6.7 to 6.9)7.0 (6.9 to 7.1)43.4 (42.9 to 43.8)45.9 (45.5 to 46.3)23.8 (23.6 to 23.9)24.8 (24.7 to 25.0)16.2 (16.0 to 16.4)16.9 (16.7 to 17.1)15.7 (15.5 to 15.9)16.4 (16.2 to 16.6)
1 exposure7.2 (7.0 to 7.3)7.1 (7.0 to 7.3)47.1 (46.5 to 47.7)45.8 (45.3 to 46.4)24.8 (24.6 to 25.1)24.3 (24.1 to 24.6)17.2 (16.9 to 17.5)16.9 (16.6 to 17.2)17.0 (16.8 to 17.3)16.6 (16.4 to 16.9)
2 exposures7.2 (6.9 to 7.3)6.8 (6.7 to 7.0)49.1 (48.3 to 49.8)45.8 (45.1 to 46.5)25.7 (25.4 to 26.1)24.4 (24.1 to 24.7)18.1 (17.7 to 18.4)17.2 (16.9 to 17.6)17.4 (17.1 to 17.7)16.5 (16.2 to 16.8)
3 exposures7.4 (7.2 to 7.6)6.9 (6.8 to 7.2)50.5 (49.7 to 51.2)46.0 (45.3 to 46.7)26.3 (25.9 to 26.6)24.5 (24.2 to 24.8)18.5 (18.2 to 18.8)17.3 (16.9 to 17.6)18.0 (17.7 to 18.3)16.7 (16.3 to 17.0)
p value for linear trend<0.0010.403<0.0010.894<0.0010.022<0.0010.017<0.0010.192
Outcomes measured at phase 7
No exposure6.7 (6.6 to 6.8)6.9 (6.8 to 7.0)40.8 (40.4 to 41.3)42.5 (42.0 to 43.9)23.7 (23.5 to 23.9)24.4 (24.3 to 24.6)15.1 (14.9 to 15.3)15.5 (15.4 to 15.7)15.0 (14.8 to 15.1)15.4 (15.3 to 15.6)
1 exposure7.1 (6.9 to 7.3)6.9 (6.8 to 7.1)44.3 (43.7 to 44.9)42.6 (42.0 to 43.2)24.9 (24.7 to 25.2)24.2 (23.9 to 24.4)16.2 (15.9 to 16.4)15.7 (15.5 to 16.0)16.0 (15.7 to 16.2)15.4 (15.2 to 15.7)
2 exposures7.4 (7.2 to 7.5)7.0 (6.8 to 7.2)46.2 (45.5 to 47.0)42.8 (42.1 to 43.6)25.8 (25.5 to 26.1)24.4 (24.1 to 24.7)17.1 (16.7 to 17.4)16.1 (15.8 to 16.5)16.6 (16.3 to 16.9)15.6 (15.3 to 15.9)
3 exposures7.4 (7.2 to 7.6)6.9 (6.7 to 7.1)47.2 (46.5 to 48.0)42.9 (42.1 to 43.6)26.2 (25.9 to 26.6)24.4 (24.1 to 24.7)17.2 (16.9 to 17.6)16.1 (15.7 to 16.4)17.0 (16.7 to 17.3)15.7 (15.4 to 16.0)
p value for linear trend<0.0010.812<0.0010.276<0.0010998<0.0010.001<0.0010.118
  • *Model 1 is adjusted for age and sex (at phase 5).

  • †Model 2 is adjusted for age, sex and employment grade (at phase 5).

  • AH4, Alice Heim intelligence test.