Table 5

Relative risk of RA in patients with a history of breast cancer, by accumulated time of antihormonal treatment before RA diagnosis, adjusted for age, education, age at first birth, number of children and family history of breast cancer/ovarian cancer

Cumulative exposureTamoxifenAIs
RA (n)Controls (n)OR (95% CI)RA (n)Controls (n)OR (95% CI)
<6 months271340.98 (0.65 to 1.49)27871.58 (1.02 to 2.45)
6 to <12 months14760.95 (0.53 to 1.68)9630.72 (0.36 to 1.44)
12 to <18 months8620.62 (0.30 to 1.30)12411.45 (0.76 to 2.77)
18 to <24 months11650.83 (0.43 to 1.57)12571.08 (0.58 to 2.02)
>24 months422830.74 (0.54 to 1.03)312670.57 (0.39 to 0.82)
  • AIs, aromatase inhibitors; RA, rheumatoid arthritis.