HRs for shift work exposure groups applying conditional Cox analysis of twin pairs discordant for prostate cancer (no cancer as reference) for prediction of prostate cancer after baseline among male night workers, and with 95% CI. n=332
| Duration of exposure, years | N (%) | Complete follow-up HR (95% CI)* | Follow-up to 60 years HR (95% CI)† | |
| No night work (ref) Working nights for: | 0 years 1–5 years 6–10 years 11–20 years 21–45 years | 225 (68) 42 (13) 19 (6) 22 (7) 24 (7) | 1 1.02 (0.48 to 2.18) 1.97 (0.64 to 6.02) 0.88 (0.32 to 2.43) 1.05 (0.39 to 2.84) | 1 0.88 (0.26 to 2.46) 1.24 (0.26 to 5.82) 0.87 (0.26 to 2.93) 0.57 (0.13 to 2.45) |
*Follow-up until December 31 2010.
†Follow-up until the age of 60.