Table 5.
Association between night work indicators and prostate cancer risk, stratified by chronotype
| Morning chronotype | Neither chronotype | Evening chronotype | ||||
| n=598 | n=839 | n=255 | ||||
| Cases (n=301)/controls (n=297) | OR*† | Cases (n=403)/controls (n=436) | OR*† | Cases (n=113)/controls (n=142) | OR*† | |
| Never night work | 202/181 | 1.0 (Reference) | 270/282 | 1.0 (Reference) | 60/93 | 1.0 (Reference) |
| Ever night work | 99/116 | 0.77 (0.54 to 1.10) | 133/154 | 0.96 (0.51 to 1.78) | 53/49 | 1.83 (1.05 to 3.19) |
| Permanent night work | 76/68 | 1.02 (0.68 to 1.54) | 94/109 | 0.93 (0.67 to 1.30) | 39/36 | 1.71 (0.93 to 3.14) |
| Rotating night work | 23/48 | 0.43 (0.25 to 0.75) | 43/48 | 1.02 (0.64 to 1.62) | 17/15 | 1.95 (0.84 to 4.53) |
| Total duration of night work (in years) | ||||||
| <20 | 47/68 | 0.64 (0.42 to 1.00) | 72/80 | 0.99 (0.68 to 1.44) | 25/28 | 1.57 (0.79 to 3.12) |
| <10 | 22/42 | 0.47 (0.26 to 0.82) | 49/51 | 1.11 (0.71 to 1.72) | 16/20 | 1.45 (0.65 to 3.22) |
| 10–19 | 25/26 | 0.97 (0.53 to 1.78) | 23/29 | 0.80 (0.44 to 1.45) | 9/8 | 1.80 (0.62 to 5.19) |
| ≥20 | 52/48 | 0.96 (0.60 to 1.54) | 61/74 | 0.92 (0.62 to 1.36) | 28/21 | 2.14 (1.06 to 4.30) |
| 20–29 | 19/16 | 1.11 (0.54 to 2.29) | 22/34 | 0.74 (0.42 to 1.32) | 9/8 | 1.64 (0.56 to 4.82) |
| ≥30 | 33/32 | 0.90 (0.51 to 1.58) | 39/40 | 1.07 (0.66 to 1.74) | 19/13 | 2.46 (1.07 to 5.61) |
| p-trend | 0.74 | 0.78 | 0.01 | |||
| Total frequency of night work (number of cumulative nights) | ||||||
| <1314 | 41/61 | 0.60 (0.38 to 0.95) | 64/72 | 0.98 (0.66 to 1.44) | 26/26 | 1.79 (0.90 to 3.55) |
| ≥1314 | 58/55 | 0.98 (0.63 to 1.54) | 69/82 | 0.94 (0.65 to 1.37) | 27/23 | 1.87 (0.93 to 3.75) |
| p-trend | 0.89 | 0.57 | 0.26 | |||
| Number of consecutive nights | ||||||
| <6 | 46/56 | 0.74 (0.47 to 1.17) | 71/93 | 0.83 (0.58 to 1.21) | 27/24 | 1.91 (0.96 to 3.78) |
| ≥6 | 49/46 | 1.01 (0.63 to 1.62) | 51/41 | 1.33 (0.84) | 23/21 | 2.00 (0.95 to 4.24) |
| p-trend | 0.67 | 0.24 | 0.95 | |||
| Shift length (hours) | ||||||
| ≤10 | 34/68 | 0.44 (0.27 to 0.71) | 57/83 | 0.79 (0.53 to 1.16) | 23/26 | 1.57 (0.77 to 3.22) |
| >10 | 24/14 | 1.70 (0.83 to 3.47) | 22/18 | 1.37 (0.71 to 2.67) | 8/6 | 2.08 (0.65 to 6.62) |
| p-trend | 0.51 | 0.94 | 0.07 | |||
| Duration (years) × number of consecutive nights | ||||||
| <20 × <6 nights | 25/39 | 0.59 (0.34 to 1.03) | 45/50 | 0.98 (0.62 to 1.54) | 17/17 | 1.63 (0.74 to 3.58) |
| ≥20 × <6 nights | 21/17 | 1.09 (0.53 to 2.22) | 26/43 | 0.65 (0.38 to 1.11) | 10/7 | 2.16 (0.73 to 6.37) |
| <20 × ≥6 nights | 20/21 | 0.93 (0.48 to 1.80) | 22/23 | 1.01 (0.54 to 1.89) | 6/9 | 1.25 (0.37 to 4.29) |
| ≥20 × ≥6 nights | 29/25 | 1.09 (0.59 to 2.02) | 29/18 | 1.74 (0.93 to 3.26) | 17/12 | 2.26 (0.93 to 5.49) |
| Duration (years) x shift length (hours) | ||||||
| <20 × ≤10 | 13/41 | 0.30 (0.15 to 0.59) | 31/42 | 0.83 (0.50 to 1.38) | 10/19 | 1.02 (0.41 to 2.54) |
| ≥20 × ≤10 | 21/27 | 0.65 (0.33 to 1.25) | 26/41 | 0.73 (0.42 to 1.26) | 13/7 | 2.77 (0.99 to 7.78) |
| <20 × >10 | 11/6 | 1.97 (0.69 to 5.60) | 10/11 | 1.01 (0.41 to 2.50) | 3/2 | 1.92 (0.30 to 12.24) |
| ≥20 × >10 | 13/8 | 1.52 (0.60 to 3.88) | 12/7 | 1.91 (0.73 to 5.04) | 5/4 | 2.12 (0.50 to 9.02) |
| Shift length (hours) × total frequency of night work (number of cumulative nights) | ||||||
| ≤10 × < 1314 nights | 14/37 | 0.35 (0.18 to 0.68) | 27/40 | 0.78 (0.46 to 1.33) | 13/17 | 1.45 (0.60 to 3.48) |
| ≤10 × ≥ 1314 nights | 20/21 | 0.52 (0.27 to 0.98) | 30/43 | 0.79 (0.47 to 1.33) | 10/9 | 1.75 (0.60 to 5.07) |
| >10 × < 1314 nights | 7/5 | 1.46 (0.44 to 4.79) | 8/6 | 1.36 (0.45 to 4.14) | 2/3 | 0.75 (0.11 to 4.93) |
| >10 × ≥ 1314 nights | 17/9 | 1.93 (0.80 to 4.63) | 14/12 | 1.33 (0.59 to 3.00) | 6/3 | 3.70 (0.82 to 16.67) |
| Shift length (hours) × number of consecutive nights | ||||||
| ≤10 × <6 nights | 18/37 | 0.43 (0.23 to 0.79) | 33/54 | 0.72 (0.44 to 1.17) | 14/14 | 1.72 (0.71 to 4.19) |
| ≤10 × ≥6 nights | 16/28 | 0.48 (0.24 to 0.95) | 23/22 | 1.13 (0.60 to 2.11) | 9/12 | 1.35 (0.49 to 3.76) |
| >10 × <6 nights | 4/5 | 0.85 (0.22 to 3.29) | 7/8 | 1.01 (0.34 to 2.93) | 4/2 | 2.52 (0.42 to 15.19) |
| >10 × ≥6 nights | 17/9 | 1.92 (0.81 to 4.58) | 14/9 | 1.62 (0.68 to 3.90) | 4/3 | 2.57 (0.53 to 12.54) |
*Adjusted for age, family history of prostate cancer, race, education level.
†95% CI.