Characteristics | Referents (n = 635) | Cases (n = 635) | ||
Shift work (n = 340) | Day work (n = 295) | Shift work (n = 354) | Day work (n = 281) | |
Age at recruitment (median in year) | 35.7 | 36.2 | 35.9 | 36.2 |
High blood pressure* (% with SBP ⩾160 or DBP ⩾95) | 23.8 | 22.9 | 25.6 | 28.8 |
Overweight (% with BMI ⩾30) | 3.1 | 5.3 | 3.2 | 4.2 |
Smoking | ||||
Unknown | 30.3 | 44.0 | 27.4 | 44.5 |
Non-smokers | 22.7 | 17.0 | 18.6 | 13.9 |
Smokers | 47.0 | 39.0 | 54.0 | 41.6 |
Social class | ||||
Class III: skilled (non-manual and manual) | 21.8 | 59.0 | 19.8 | 52.0 |
Class IV: partially skilled | 52.0 | 21.7 | 56.5 | 21.3 |
Class V: unskilled | 21.2 | 19.3 | 23.7 | 26.7 |
*117 workers had neither pre-SBP nor pre-DBP; percentages are based on those with data.