Table 3.
Associations between combined night work indicators and prostate cancer risk
| Ever night work | Permanent night work | Rotating night work | ||||
| Cases (n=818)/controls (n=875) | OR*† | Cases (n=742)/controls (n=769) | OR*† | Cases (n=616)/controls (n=667) | OR*† | |
| Never night work | 532/556 | 1.0 (reference) | 532/556 | 1.0 (reference) | 532/556 | 1.0 (reference) |
| Duration and number of consecutive nights | ||||||
| <20 years and < 6 nights | 87/106 | 0.89 (0.65 to 1.23) | 57/56 | 1.06 (0.71 to 1.58) | 34/57 | 0.68 (0.43 to 1.06) |
| <10 years and < 6 nights | 56/73 | 0.84 (0.58 to 1.23) | 32/36 | 0.95 (0.57 to 1.57) | 27/41 | 0.74 (0.44 to 1.23) |
| 10–19 years and < 6 nights | 31/33 | 0.97 (0.57 to 1.63) | 25/20 | 1.24 (0.67 to 2.31) | 7/16 | 0.50 (0.20 to 1.24) |
| <20 years and ≥ 6 nights | 49/53 | 1.01 (0.67 to 1.54) | 35/33 | 1.21 (0.74 to 2.00) | 16/19 | 0.86 (0.42 to 1.74) |
| <10 years and ≥ 6 nights | 24/28 | 0.94 (0.53 to 1.67) | 14/17 | 0.96 (0.46 to 2.00) | 12/12 | 0.92 (0.39 to 2.16) |
| 10–19 years and ≥ 6 nights | 25/25 | 1.07 (0.60 to 1.92) | 21/16 | 1.46 (0.75 to 2.86) | 4/7 | 0.74 (0.21 to 2.58) |
| ≥20 years and < 6 nights | 57/67 | 0.87 (0.59 to 1.29) | 38/42 | 0.91 (0.57 to 1.46) | 24/26 | 0.94 (0.52 to 1.71) |
| 20–29 years and < 6 nights | 23/27 | 0.86 (0.48 to 1.55) | 14/20 | 0.74 (0.36 to 1.50) | 14/10 | 1.25 (0.53 to 2.95) |
| ≥30 years and < 6 nights | 34/40 | 0.88 (0.54 to 1.43) | 24/22 | 1.09 (0.59 to 1.99) | 10/16 | 0.72 (0.32 to 1.63) |
| ≥20 years and ≥ 6 nights | 75/55 | 1.45 (0.99 to 2.13) | 58/43 | 1.42 (0.92 to 2.18) | 10/8 | 1.27 (0.49 to 3.33) |
| 20–29 years and ≥ 6 nights | 23/23 | 1.14 (0.62 to 2.08) | 19/19 | 1.08 (0.56 to 2.10) | 5/4 | 1.34 (0.35 to 5.17) |
| ≥30 years and ≥ 6 nights | 52/32 | 1.71 (1.06 to 2.76) | 39/24 | 1.75 (1.01 to 3.03) | 5/4 | 1.22 (0.31 to 4.75) |
| Duration and shift length | ||||||
| <20 years and ≤ 10 hours | 55/102 | 0.60 (0.42 to 0.85) | 14/27 | 0.61 (0.31 to 1.20) | 41/71 | 0.63 (0.42 to 0.96) |
| <10 years and ≤ 10 hours | 39/62 | 0.71 (0.46 to 1.09) | 8/11 | 0.89 (0.35 to 2.26) | 32/49 | 0.70 (0.44 to 1.13) |
| 10–19 years and ≤ 10 hours | 16/40 | 0.42 (0.22 to 0.77) | 6/16 | 0.43 (0.17 to 1.13) | 9/22 | 0.48 (0.21 to 1.06) |
| <20 years and > 10 hours | 24/19 | 1.39 (0.74 to 2.59) | 16/12 | 1.46 (0.68 to 3.16) | 9/5 | 1.95 (0.64 to 6.00) |
| <10 years and > 10 hours | 13/11 | 1.31 (0.57 to 3.01) | 6/7 | 1.06 (0.35 to 3.23) | 7/4 | 1.73 (0.49 to 6.11) |
| 10–19 years and > 10 hours | 11/8 | 1.47 (0.58 to 3.74) | 10/5 | 1.99 (0.66 to 5.94) | 2/1 | 2.76 (0.25 to 30.78) |
| ≥20 years and ≤ 10 hours | 60/75 | 0.83 (0.57 to 1.21) | 20/40 | 0.51 (0.29 to 0.90) | 31/30 | 1.03 (0.60 to 1.77) |
| 20–29 years and ≤ 10 hours | 23/25 | 0.94 (0.52 to 1.71) | 4/14 | 0.28 (0.09 to 0.87) | 18/12 | 1.43 (0.66 to 3.08) |
| ≥30 years and ≤ 10 hours | 37/50 | 0.77 (0.48 to 1.22) | 16/26 | 0.65 (0.34 to 1.25) | 13/18 | 0.75 (0.36 to 1.59) |
| ≥20 years and > 10 hours | 30/19 | 1.73 (0.95 to 3.16) | 22/10 | 2.35 (1.08 to 5.11) | 3/5 | 0.63 (0.15 to 2.75) |
| 20–29 years and > 10 hours | 10/10 | 1.07 (0.43 to 2.66) | 8/5 | 1.69 (0.53 to 5.34) | 1/2 | 0.41 (0.03 to 4.94) |
| ≥30 years and > 10 hours | 20/9 | 2.49 (1.11 to 5.61) | 14/5 | 3.07 (1.07 to 8.80) | 2/3 | 0.82 (0.13 to 4.95) |
| Shift length and total frequency of night work (cumulative number of nights) | ||||||
| ≤10 hours and < 1314 nights | 55/94 | 0.64 (0.45 to 0.93) | 12/17 | 0.77 (0.36 to 1.66) | 47/77 | 0.66 (0.45 to 0.98) |
| ≤10 hours and ≥ 1314 nights | 60/83 | 0.74 (0.51 to 1.08) | 22/50 | 0.47 (0.27 to 0.80) | 25/24 | 1.06 (0.59 to 1.93) |
| >10 hours and < 1314 nights | 17/14 | 1.24 (0.59 to 2.58) | 9/8 | 1.13 (0.42 to 3.02) | 7/5 | 1.39 (0.43 to 4.53) |
| >10 hours and ≥ 1314 nights | 37/24 | 1.76 (1.03 to 3.03) | 29/14 | 2.36 (1.21 to 4.56) | 5/5 | 1.16 (0.33 to 4.13) |
| Shift length and number of consecutive nights | ||||||
| ≤10 hours and < 6 nights | 65/105 | 0.68 (0.48 to 0.96) | 13/26 | 0.54 (0.27 to 1.09) | 50/76 | 0.72 (0.49 to 1.06) |
| ≤10 hours and ≥ 6 nights | 49/62 | 0.81 (0.54 to 1.22) | 18/33 | 0.58 (0.32 to 1.07) | 22/24 | 0.93 (0.50 to 1.71) |
| >10 hours and < 6 nights | 15/15 | 1.10 (0.52 to 2.32) | 4/7 | 0.60 (0.16 to 2.15) | 8/7 | 1.24 (0.44 to 3.55) |
| >10 hours and ≥ 6 nights | 35/21 | 1.86 (1.05 to 3.27) | 30/13 | 2.57 (1.31 to 5.06) | 4/3 | 1.36 (0.29 to 6.26) |
*Adjusted for age, family history of prostate cancer, race, education level.
†95% CI.