Table 2 Age group-adjusted associations between risk of breast cancer and exposure to graveyard shift, light at night, phase shift and sleep disruption
From: The association between different night shiftwork factors and breast cancer: a case–control study
Exposure | Controls | Cases | OR (95% CI) |
|---|---|---|---|
Graveyard shift | |||
Never | 1404 | 914 | Reference |
Ever | 381 | 288 | 1.16 (0.97–1.38) |
Duration of exposure | |||
<10 years | 199 | 164 | 1.25 (1.00–1.56) |
10–<20 years | 98 | 71 | 1.09 (0.79–1.50) |
20+ years | 84 | 53 | 1.02 (0.71–1.45) |
Light at night | |||
Never | 1447 | 947 | Reference |
Ever | 335 | 253 | 1.15 (0.96–1.38) |
Highest dose of exposure | |||
Low | 3 | 0 | * |
Medium | 160 | 110 | 1.06 (0.82–1.37) |
High | 172 | 143 | 1.25 (0.98–1.59) |
Duration of exposure at medium and/or high levels | |||
<10 years | 186 | 153 | 1.25 (0.99–1.57) |
10–<20 years | 80 | 65 | 1.21 (0.86–1.70) |
20+ years | 66 | 35 | 0.84 (0.55–1.28) |
Phase shift | |||
None | 1476 | 959 | Reference |
Ever | 309 | 242 | 1.22 (1.01–1.47) |
Highest dose of exposure | |||
Low | 51 | 36 | 1.09 (0.70–1.68) |
Medium | 1.21177 | 140 | 1.24 (0.97–1.57) |
High | 81 | 66 | 1.25 (0.90–1.75) |
Duration of exposure at medium and/or high levels | |||
<10 years | 160 | 140 | 1.35 (1.06–1.72) |
10–<20 years | 58 | 42 | 1.12 (0.74–1.68) |
20+ years | 40 | 24 | 0.96 (0.58–1.61) |
Sleep disruption | |||
None | 1618 | 1067 | Reference |
Ever | 158 | 127 | 1.21 (0.95–1.55) |
Highest dose of exposure | |||
Low | 49 | 41 | 1.27 (0.83–1.94) |
Medium | 40 | 34 | 1.25 (0.79–2.00) |
High | 69 | 52 | 1.14 (0.79–1.66) |
Duration of exposure at medium and/or high levels | |||
<10 years | 61 | 55 | 1.32 (0.91–1.92) |
10–<20 years | 27 | 16 | 0.87 (0.46–1.63) |
20+ years | 21 | 15 | 1.15 (0.59–2.25) |
