Supplemental table s1. 1st TNFi of the switchers: Disease activity levels and response rates according to reason for subsequent switch to a 2nd TNFi

IR switchers / AE switchers
n=30 / n=44
Baseline
n=30 / 3 months
n=26 / Last observation†
n=28 / Baseline
n=44 / 3 months
n=35 / Last observation‡
n=38
BASDAI 50, n (%)* / - / 1 (10.0) / 1 (9.1) / - / 4 (30.8) / 5 (33.3)
ASAS20, n (%)* / - / 5 (50.0) / 2 (20.0) / - / 5 (41.7) / 5 (41.7)
ASAS40, n (%)* / - / 2 (20.0) / 0 (0.0) / - / 4 (33.3) / 4 (30.8)
BASFI (0-10)* / 6.6 (4.3-7.9) / 5.2 (3.7-6.4) / 5.6 (4.7-6.3) / 4.8 (3.1-5.9) / 2.5 (1.6-6.7) / 2.7 (2.4-7.6)
BASDAI (0-10)* / 7.3 (6.7-8.1) / 5.5 (4.0-6.8) / 6.3 (5.1-7.7) / 6.5 (5.6-7.8) / 4.6 (2.7-7.6) / 4.6 (2.6-7.6)
ASDAS* / 4.43 (3.59-4.93) / 3.10 (2.35-3.36) / 3.53 (2.72-4.26) / 3.63 (2.96-4.11) / 2.18 (1.22-3.78) / 3.25 (1.31-4.33)
ESR, mm/h / 16 (9-30) / 9 (4-15) / 7 (4-25) / 20 (8-35) / 7 (4-14) / 8 (4-28)
CRP, mg/L / 11 (5-32) / 5 (3-15) / 5 (3-13) / 9 (5-20) / 5 (2-7) / 5 (3-11)
Patient global VAS, mm / 68 (40-79) / 37 (21-62) / 63 (39-76) / 59 (35-72) / 25 (10-51) / 47 (22-65)
Pain VAS, mm / 62 (40-76) / 40 (18-55) / 59 (46-67) / 57 (33-67) / 21 (10-43) / 40 (13-60)
Fatigue VAS, mm / 70 (52-89) / 43 (27-66) / 69 (42-77) / 61 (43-82) / 42 (22-70) / 47 (23-70)
Physician global VAS, mm / 38 (26-60) / 16 (9-22) / 27 (10-44) / 38 (28-50) / 17 (7-37) / 18 (11-28)
SF-36 PCS / 31 (22-39) / 36 (29-42) / 28 (23-35) / 27 (23-35) / 37 (28-47) / 31 (27-44)
SF-36 MCS / 47 (37-52) / 55 (38-57) / 41 (34-52) / 46 (35-54) / 50 (36-57) / 46 (36-57)
SF-6D / 0.60 (0.46-0.70) / 0.64 (0.55-0.79) / 0.58 (0.49-0.66) / 0.55 (0.50-0.67) / 0.65 (0.58-0.73) / 0.64 (0.54-0.75)

Values are medians (interquartile range) unless otherwise indicated. TNFi, Tumour Necrosis Factor inhibitor; BASFI, Bath Ankylosing Spondylitis Functional Index; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; ASDAS, Ankolosing Spondylitis Disease Activity Score; ESR, Erythrocyte Sedimentation Rate; CRP, C-reactive protein; VAS, Visual Analogue Scale; PCS, Physical Components Summary; MCS, Mental Components Summary.

*BASDAI, BASFI and ASDAS data and ASAS responses were not available for all patients, see details in the text. †3 months: n=2, 6 months: n=13, 1 year: n=5, 2 years: n=5, 3 years: n=1, 4 years: n=2. ‡3 months: n=12, 6 months: n=14, 1 year: n=5, 2 years: n=2, 3 years: n=5.