Table 3

RR of ACPA-positive RA for subjects exposed to different combinations of any vaccination and ever smoking/HLA-DRB1 alleles

VaccinationCases/controlsOR* (95%CI)Cases/controlsOR* (95%CI)
Never smokersEver smokers
No105/2361.0206/2761.7 (1.3 to 2.3)
Yes203/5020.9 (0.7 to 1.2)494/6681.7 (1.3 to 2.2)
AP†0.1 (−0.2 to 0.3)
No SE allelesAny SE alleles
VaccinationCases/controlsOR* (95%CI)Cases/controlsOR* (95%CI)
No41/1821.0306/1887.5 (5.1 to 11.0)
Yes131/3491.8 (1.2 to 2.6)657/3678.5 (5.9 to 12.4)
AP†0.0 (−0.2 to 0.2)

  • ↵* Adjusted for age, residential area and sex.

  • ↵† AP, attributable proportion due to interaction (0=no interaction).

  • ACPA, antibodies to citrullinated peptides; RA, rheumatoid arthritis; RR, relative risk; SE, shared epitope.