Demographics and disease characteristics at start of TNFi therapy
| Non-switchers (n=437) | Switchers (n=77) | ||
|---|---|---|---|
| 1st TNFi | 1st TNFi | 2nd TNFi | |
| Age (years) | 42 (35–50) | 42 (34–50) | 44 (36–52) |
| Male sex (n (%)) | 316 (72.3) | 50 (64.9) | – |
| HLA-B27 positive (n (%)) | 296 (93.1) | 58 (89.2) | – |
| Etanercept (n (%)) | 232 (53.1) | 32 (41.6) | 31 (40.3) |
| Infliximab (n (%)) | 139 (31.8) | 41 (53.2) | 18 (23.4) |
| Adalimumab (n (%)) | 66 (15.1) | 4 (5.2) | 28 (36.4) |
| DMARD co-medication (n (%)) | 104 (23.8) | 16 (20.8) | 17 (22.1) |
| Disease duration (years) | 11 (4–20) | 10 (5–14) | 11 (6–18) |
| No of previous DMARDs | 0 (0–1) | 0 (0–1) | 1 (0–2) |
| BASFI (0–10)* | 4.5 (2.7–6.0) | 5.3 (3.2–6.9) | 5.4 (2.9–6.8) |
| BASDAI (0–10)* | 5.7 (4.1–6.9)† | 6.7 (5.6–7.8)† | 6.0 (4.0–7.3) |
| ASDAS* | 3.36 (2.83–4.12) | 3.70 (3.13–4.32) | 3.69 (2.87–4.39) |
| ESR (mm/h) | 18 (10–35) | 16 (8–31) | 22 (5–39) |
| CRP (mg/l) | 12 (5–28) | 9 (5–21) | 10 (5–27) |
| Patient global VAS (mm) | 58 (38–75) | 60 (37–75) | 60 (36–79) |
| Pain VAS (mm) | 53 (34–69) | 59 (38–72) | 58 (44–73) |
| Fatigue VAS (mm) | 61 (35–79) | 63 (44–82) | 63 (38–80) |
| Physician global VAS (mm) | 36 (25–51) | 38 (27–54) | 37 (25–59) |
| SF-36 PCS | 31 (25–38) | 30 (23–38) | 28 (24–35) |
| SF-36 MCS | 46 (34–54) | 46 (36–52) | 44 (36–54) |
| SF-6D | 0.58 (0.52–0.65) | 0.58 (0.49–0.67) | 0.55 (0.48–0.64) |
Values are median (IQR) unless otherwise indicated.
↵* BASDAI, BASDAI and ASDAS data were not available for all patients (see details in text).
↵† Non-switchers first vs switchers first (p=0.003).
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; CRP, C reactive protein; DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; HLA, human leucocyte antigen; MCS, mental components summary; PCS, physical components summary; SF-36, 36-item Short-Form Health Survey; TNFi, tumour necrosis factor inhibitor; VAS, Visual Analogue Scale.