Table 4

Shift work by hormone receptor status

Years shift work history*Controls (n=1179)ER/PR+ (n=840)ER/PR− (n=166)Interaction by ER/PR status‡
n (%)n (%)OR†95% CIn (%)OR†95% CI
None773 (65.6)547 (65.1)116 (69.9)
0–14312 (26.5)216 (25.7)1.000.81 to 1.2337 (22.3)0.780.52 to 1.17p=0.22
15–2981 (6.9)55 (6.6)0.970.68 to 1.3911 (6.6)0.900.47 to 1.75p=0.84
≥3013 (1.1)22 (2.6)2.371.18 to 4.762 (1.2)1.060.24 to 4.75p=0.27
  • *Using 50% of time definition.

  • †Model adjusted for age and centre.

  • ‡p Values calculated from case-only model comparing ER/PR+ and ER/PR− groups.

  • ER, oestrogen; PR, progesterone.