Table 1.
Baseline characteristics by age group
| <75 years old | ≥75 years old | Stat. imbalance | |
|---|---|---|---|
| Total cohort, n (%) | 14 932 (95.1) | 768 (4.9) | |
| Age, yrs, | 55 (46–63) | 77 (76–80) | |
| Female sex, n (%) | 10 788 (72.3) | 627 (81.6) | <0.001b |
| Smoking status, n (%) | |||
| Current | 2648 (22.3) | 43 (7.0) | <0.001b |
| Ever | 7597 (61.6) | 393 (60.3) | 0.53b |
| Comorbidity (RDCI score ≥1), n (%) | 8303 (55.6) | 551 (71.7) | <0.001b |
| Cardiac (MI, stroke, angina) | 968 (6.5) | 133 (17.3) | <0.001b |
| Respiratory (asthma, COPD) | 2080 (13.9) | 129 (16.9) | <0.03b |
| Seropositive (RF), n (%) | 8437 (58.7) | 485 (64.3) | <0.002b |
| Disease duration, yrs | 10 (5–18) | 14 (7–23) | <0.0001a |
| Number of previous csDMARDs | 3 (2–5) | 3 (2–5) | 0.33a |
| TNFi, n (%) | 0.82b | ||
| Infliximab | 3955 (26.5) | 209 (27.2) | |
| Etanercept | 5374 (36.0) | 265 (34.5) | |
| Adalimumab | 4744 (31.8) | 246 (32.0) | |
| Certolizumab | 859 (5.8) | 48 (6.3) | |
| TNFi monotherapy, n (%) | 3642 (24.4) | 268 (34.9) | <0.001b |
| TNFi/csDMARDs combination | |||
| Methotrexate | 5776 (38.7) | 252 (33.8) | |
| Sulfasalazine | 430 (2.9) | 21 (2.7) | |
| Leflunomide | 667 (4.5) | 43 (5.6) | |
| Two csDMARDs | 2930 (19.6) | 111 (14.5) | |
| Three csDMARDs | 781 (5.2) | 30 (3.9) | |
| Other combination | 706 (4.7) | 43 (5.6) | |
| Prednisolone, n (%) | 5867 (39.3) | 401 (52.2) | <0.001b |
| DAS28-ESR, mean (s.d.) | 6.42 (1.1) | 6.52 (1.0) | 0.01a |
| SJC28, mean (s.d.) | 10.7 (6.2) | 10.6 (6.0) | 0.84a |
| TJC28, mean (s.d.) | 15.2 (7.5) | 15.1 (7.9) | 0.67a |
| Global VAS | 75 (62-87) | 75 (60–87) | 0.20a |
| ESR | 38 (21–61) | 43 (26–68) | <0.0001a |
| CRP mg/l | 26 (11–56) | 29 (13–60) | 0.12a |
| HAQ, median (IQR) | 2.125 (1.625-2.375) | 2.25 (2–2.625) | <0.0001 |
All values are gives as median (IQR), unless otherwise specified by n (%) or mean (s.d.).
a
Statistical imbalance tested by kwallis.
b
Statistical imbalance tested by χ2.
TNFi: TNF inhibitor; RDCI: Rheumatic Disease Comorbidity Index; DAS28: Disease Activity Score 28 Joints; SJC28: 28 swollen joint count; TJC28: 28 tender joint count; Global VAS: visual analogue scale for patient’s global assessment.