Odds ratio (OR) with 95% CI of developing ACPA-positive RA, ACPA-negative RA and RA overall, respectively, among men exposed to stone dust, rock drilling, stone crushing and silica overall, respectively, compared with men unexposed to silica
| Exposure | Category of RA | Number of exposed cases/exposed controls | OR* | 95% CI |
|---|---|---|---|---|
| Stone dust | ACPA-positive RA | 44/58 | 1.60 | 1.04 to 2.44 |
| ACPA-negative RA | 17/58 | 1.02 | 0.57 to 1.82 | |
| RA overall | 67/58 | 1.38 | 0.95 to 2.02 | |
| Rock-drilling | ACPA-positive RA | 18/17 | 2.34 | 1.17 to 4.68 |
| ACPA-negative RA | 5/17 | 0.96 | 0.34 to 2.67 | |
| RA overall | 26/17 | 1.83 | 0.97 to 3.43 | |
| Stone crushing | ACPA-positive RA | 11/13 | 2.03 | 0.88 to 4.67 |
| ACPA-negative RA | 5/13 | 1.34 | 0.45 to 3.97 | |
| RA overall | 17/13 | 1.62 | 0.77 to 3.43 | |
| Silica overall | ACPA-positive RA | 54/69 | 1.67 | 1.13 to 2.48 |
| ACPA-negative RA | 20/69 | 0.98 | 0.57 to 1.66 | |
| RA overall | 80/69 | 1.39 | 0.98 to 1.96 |
↵* OR adjusted for the potential confounding from age and residential area.
ACPA, antibodies against citrullinated peptide antigens; RA, rheumatoid arthritis.