Evaluation of the nonsteroidal anti-inflammatory drug-sparing effect of etanercept in axial spondyloarthritis: results of the multicenter, randomized, double-blind, placebo-controlled SPARSE study

Table 1 Baseline demographics and disease characteristics

	Etanercept 50 mg/etanercept 50 mg (n= 42)	Placebo/etanercept 50 mg (n= 48)
Baseline patient characteristics
Age (years)	38.8 (12.3)	38.9 (11.4)
Female	18 (42.9%)	16 (33.3%)
White	40 (95.2%)	48 (100.0%)
Weight (kg)	73.8 (14.2)	75.4 (15.2)
Body mass index (kg/m²)	25.7 (4.8)	25.9 (4.9)
Human leukocyte antigen-B27–positive	28 (66.7%)	31 (64.6%)
Disease characteristics
Duration since diagnosis of ankylosing spondylitis (years)	6.0 (9.0)	5.5 (7.4)
Past history or present symptoms
Arthritis	11 (26.2%)	18 (37.5%)
Inflammatory back pain	40 (95.2%)	48 (100.0%)
Enthesitis	25 (59.5%)	33 (68.8%)
Dactylitis	4 (9.5%)	8 (16.7%)
Psoriasis	9 (21.4%)	9 (18.8%)
Uveitis	5 (11.9%)	3 (6.3%)
Family history
Ankylosing spondylitis	9 (21.4%)	4 (8.3%)
Rheumatoid arthritis	2 (4.8%)	3 (6.3%)
Inflammatory bowel disease	2 (4.8%)	1 (2.1%)
Uveitis	2 (4.8%)	0 (0%)
Positive pelvic X-ray	24 (57.1%)	27 (56.3%)
MRI sacroiliitis positive	21 (50.0%)	24 (50.0%)
NSAID intake
ASAS-NSAID score^a	98.2 (39.0)	93.0 (23.4)
Disease activity
BASDAI (0 to 100)	6.0 (1.6)	5.9 (1.5)
ASDAS-CRP	3.4 (0.9)	3.2 (0.8)
ASDAS-CRP disease state^b
Inactive disease	0 (0%)	0 (0%)
Moderate disease activity	5 (11.9%)	3 (7.0%)
High disease activity	19 (45.2%)	23 (53.5%)
Very high disease activity	18 (42.9%)	17 (39.5%)
PGA of disease activity (0 to 10)	6.4 (1.5)	6.2 (1.3)
Total back pain (0 to 100)	6.7 (1.7)	6.4 (1.8)
BASFI (0 to 100)	5.2 (2.1)	5.1 (2.2)
BASMI (0 to 10)	2.6 (1.8)	2.6 (1.6)
C-reactive protein level (mg/dl)	1.0 (1.3)	0.9 (1.4)
Normal C-reactive protein level^c	21 (50.0%)	28 (65.1%)

Safety population; data presented as mean (standard deviation) or n (%).ASAS, Assessment of SpondyloArthritis International Society; ASDAS-CRP, Ankylosing Spondylitis Disease Activity Score on the basis of C-reactive protein; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Function Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; MRI, magnetic resonance imaging; NSAID, nonsteroidal anti-inflammatory drug; PGA, Physician Global Assessment. ^aLast observation carried forward, with imputation, intent-to-treat population. ^bInactive disease = ASDAS-CRP <1.3; moderate disease activity = 1.3 ≤ ASDAS-CRP <2.1; high disease activity = 2.1 ≤ ASDAS-CRP <3.5; very high disease activity = ASDAS-CRP ≥3.5. ^cNormal CRP = ≤1.25 × the upper limit of normal (4.9 mg/l).

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