Variables | RA-ILD | RA-non ILD | P |
---|---|---|---|
( n = 148) | ( n = 410) | ||
Sex, female | 95 (64.2) | 350 (85.4) | < 0.001 |
Age, years | 65.8 ± 9.9 | 58.0 ± 10.4 | < 0.001 |
BMI (n = 74, 250) | 23.6 ± 3.5 | 23.0 ± 3.2 | 0.055 |
 BMI < 23 kg/m2 | 61 (41.2) | 201 (49.0) | 0.103 |
 BMI ≥ 23 kg/m2 | 87 (58.8) | 209 (51.0) | |
Smoking history | |||
 Never smoker | 91 (61.5) | 336 (82.0) | < 0.001 |
 Ever smoker | 57 (38.5) | 74 (18.0) | |
  Pack-years of cigarettes smoked (n = 57, 74) | 31.0 ± 24.6 | 21.7 ± 16.2 | 0.018 |
CCI scorea | 0 (0, 1) | 0 (0, 0) | < 0.001 |
Disease duration of RA-ILD, years | 2.1 ± 1.8 | N/A | N/A |
ILD on chest X-ray | 107 (72.3) | N/A | N/A |
Age of RA diagnosis, years | 57.4 ± 11.3 | 47.1 ± 12.0 | < 0.001 |
 Late-onset RA | 65 (43.9) | 58 (14.2) | < 0.001 |
 Younger-onset RA | 83 (56.1) | 352 (85.9) | |
Disease duration of RA, years | 8.4 ± 7.0 | 10.9 ± 7.5 | < 0.001 |
Disease activity of RA | |||
 DAS28-ESR | 3.7 ± 1.4 | 3.4 ± 1.2 | 0.007 |
 DAS28-CRP | 2.5 ± 1.1 | 2.4 ± 1.0 | 0.234 |
 CDAI | 10.9 ± 8.9 | 9.9 ± 7.3 | 0.358 |
 SDAI | 11.9 ± 9.9 | 10.3 ± 7.6 | 0.156 |
Quality of life | |||
 HAQ-DI | 0.9 ± 0.7 | 0.7 ± 0.6 | 0.002 |
  HAQ-DI ≥1 | 66 (44.6) | 127 (31.0) | < 0.001 |
  HAQ-DI <1 | 82 (55.4) | 283 (69.0) | |
 EQ-5D | 0.7 ± 0.2 | 0.8 ± 0.1 | < 0.001 |
Laboratory test | |||
 RF positivity | 132 (89.2) | 330 (80.5) | 0.016 |
 Anti-CCP positivity (n = 145, 410) | 134 (91.8) | 373 (91.2) | 0.830 |
 Either RF or anti-CCP positivity | 141 (95.3) | 397 (96.8) | 0.382 |
 ESR, mm/hr | 38.5 ± 27.5 | 26.5 ± 20.4 | < 0.001 |
 CRP, mg/dL | 1.0 ± 1.8 | 0.5 ± 0.8 | < 0.001 |
Medications | |||
 Conventional synthetic DMARDs | |||
  Methotrexate | 80 (54.1) | 339 (82.7) | < 0.001 |
  Sulfasalazine | 60 (40.5) | 75 (18.3) | < 0.001 |
  Hydroxychloroquine | 63 (42.6) | 74 (18.1) | < 0.001 |
  Leflunomide | 8 (5.4) | 100 (24.4) | < 0.001 |
  Tacrolimus | 24 (16.2) | 39 (9.5) | 0.027 |
 Biologic DMARDs | 25 (16.9) | 83 (20.2) | 0.376 |
  TNF inhibitorsb | 9 (6.1) | 65 (15.9) | 0.003 |
  Non-TNF inhibitorsc | 16 (10.8) | 18 (4.4) | 0.005 |
 Targeted synthetic DMARDd | 1 (0.7) | 14 (3.4) | 0.133 |
 Oral glucocorticoids | 81 (54.7) | 96 (23.4) | < 0.001 |
  Glucocorticoids dosee, mg/day | 4.9 ± 3.1 | 3.0 ± 1.6 | < 0.001 |
 Anti-fibrotic agentsf | 1 (0.7) | N/A | N/A |