Arthritis conditions associated with coal and silica exposure, adjusted for smoking and age combined datasets (2017 and 2019 surveys)
| Arthritis (Any Type) | Non-RA arthritis (Excluding RA) | RA* (Excluding non-RA) | |
| (n=2981) | (n=2667) | (n=1607) | |
| Arthritis prevalence | 57% (55%–58%) | 46% (44%–48%) | 11% (9%–12%) |
| Risk factors | Odds Ratios (95% confidence intervals) | ||
| Coal and silica exposure | |||
| Coal (±silica exposure) | 2.3 (1.8 to 2.8) | 2.1 (1.7 to 2.5) | 3.5 (2.5 to 4.9) |
| Silica exposure only | 2.0 (1.7 to 2.4) | 1.8 (1.5 to 2.2) | 3.2 (2.4 to 4.4) |
| Neither | Referent | Referent | Referent |
| Age | 1.02 (1.01 to 1.03) | 1.02 (1.01 to 1.03) | 1.02 (1.01 to 1.03) |
| Smoking | |||
| Current/recent smoker | 1.1 (0.9 to 1.4) | 1.0 (0.8 to 1.3) | 1.7 (1.2 to 2.5) |
| Former smoker | 1.3 (1.1 to 1.5) | 1.3 (1.1 to 1.5) | 1.5 (1.2 to 2.1) |
| Never smoked | Referent | Referent | Referent |
OR for age expressed per year of age. Recent smokers include those who stopped in past 3 years.
*RA definition based on report of doctor’s diagnosis of RA, plus treatment with glucocorticoids.
RA, rheumatoid arthritis.