The prevalence and clinical characteristics of nonradiographic axial spondyloarthritis among patients with inflammatory back pain in rheumatology practices: a multinational, multicenter study

Table 6 Clinical outcomes and patient-reported outcome measures for patients with nonradiographic axial spondyloarthritis, ankylosing spondylitis, and other inflammatory back pain

	Total (N = 686)	nr-axSpA (N = 188)	AS (N = 413)	Other IBP (N = 85)	p Value
ASDAS score (ESR)					0.003
Number of patients	619	167	378	74
Mean ± SD	2.87 ± 1.14	2.62 ± 1.17	2.97 ± 1.13	2.92 ± 1.01
ASDAS score (CRP)					0.002
Number of patients	559	149	346	64
Mean ± SD	2.81 ± 1.19	2.52 ± 1.21	2.93 ± 1.18	2.81 ± 1.17
BASDAI					0.010
Number of patients	681	186	412	83
Mean ± SD	4.44 ± 2.24	4.03 ± 2.32	4.56 ± 2.17	4.77 ± 2.29
BASFI					<0.001
Number of patients	683	187	411	85
Mean ± SD	4.09 ± 2.59	3.20 ± 2.47	4.43 ± 2.57	4.38 ± 2.49
BASMI (11-point)					<0.001
Number of patients	575	154	353	68
Mean ± SD	3.55 ± 2.03	2.41 ± 1.54	4.09 ± 2.06	3.33 ± 1.75
BASMI (3-point)					<0.001
Number of patients	564	146	347	71
Mean ± SD	2.83 ± 2.19	1.62 ± 1.51	3.40 ± 2.25	2.52 ± 2.03
BASMI (linear function)					<0.001
Number of patients	686	188	413	85
Mean ± SD	4.44 ± 2.55	3.71 ± 2.77	4.77 ± 2.38	4.47 ± 2.50

Abbreviation: AS ankylosing spondylitis, ASDAS Ankylosing Spondylitis Disease Activity Score, BASDAI Bath Ankylosing Spondylitis Disease Activity Index, BASFI Bath Ankylosing Spondylitis Functional Index, BASMI Bath Ankylosing Spondylitis Metrology Index, CRP C-reactive protein, ESR erythrocyte sedimentation rate, IBP inflammatory back pain, nr-axSpA nonradiographic axial spondyloarthritis
The p values represent the omnibus statistical comparison of percentages (or means) across IBP groups based on the F-test values

ISSN: 1478-6362