Table 4

Odds ratio (OR) with 95% CI of developing ACPA-positive RA, ACPA-negative RA and RA overall, respectively, among men with different combinations of silica exposure status and HLA-DRB1 ‘shared epitope’ (SE) status, compared with men unexposed to silica who were not carrying SE

Subjects unexposed to silicaSubjects exposed to silica
SE statusCategory of RANumber of cases/controlsOR*95% CINumber of cases/controlsOR*95% CI
No SEACPA-positive RA35/16518/162.510.97 to 6.49
ACPA-negative RA80/16516/160.840.31 to 2.27
RA overall119/165114/161.320.61 to 2.86
Any SEACPA-positive RA238/1427.865.10 to 12.1246/2111.395.10 to 22.07
ACPA-negative RA103/1421.521.04 to 2.2313/211.460.67 to 3.20
RA overall368/1423.542.59 to 4.8363/214.452.53 to 7.83
  • * OR adjusted for the potential confounding from age and residential area.

  • ACPA, antibodies against citrullinated peptide antigens; RA, rheumatoid arthritis.