Table 3.
Association between SiO2 exposure (occupational and non-occupational, by quartile) and patient characteristics
| RA patient variable | Occupational exposure score | Non-occupational exposure score | ||||
| Q1–Q3 | Q4 | P value* | Q1–Q3 | Q4 | P value* | |
| Ever-smoking, n (%) | 21 (28.8) | 16 (66.7) | 0.002 | 25 (33.8) | 12 (55.2) | 0.18 |
| ACPA-positivity, n (%) | 56 (78.9) | 22 (95.6) | 0.16 | 61 (85.9) | 17 (73.9) | 0.31 |
| Erosive RA patients, n (%) | 61 (84.7) | 19 (82.6) | 0.93 | 62 (84.9) | 18 (81.8) | 0.98 |
| bDMARD treatment n (%) |
44 (60.3) | 10 (41.7) | 0.17 | 38 (51.3) | 16 (69.6) | 0.19 |
| ILD, n (%) | 5 (10.9) | 6 (37.5) | 0.04* | 9 (19.1) | 2 (13.3) | 0.9 |
| Emphysema, n (%) |
5 (10.9) | 7 (43.7) | 0.004* | 8 (17.4) | 4 (25.0) | 0.51 |
| Mediastinal LA, n (%) | 9 (19.6) | 8 (50.0) | 0.04* | 14 (28.0) | 3 (25.0) | 0.88 |
| Lung micronodules, n (%) |
4 (8.7) | 3 (18.7) | 0.27 | 5 (10.6) | 2 (13.3) | 0.77 |
*χ2 test, level of significance p<0.05.
ACPA, anticitrullinated protein antibody; bDMARD, biologic disease-modifying antirheumatic drug; ILD, interstitial lung disease; LA, lymphadenopathy; RA, rheumatoid arthritis.