Table 3. Pooled data of subgroup analysis by diagnostic category.

Outcomes (TNFi vs. Control)	Study number	Total patient number		Heterogeneity		MD (95%CI)	P value
		TNFi	Control	I2	P
SPARCC SIJ score
nr-axSpA	4	439	453	41%	0.16	2.94[2.56, 3.31]	P<0.00001*
AS	2	64	64	0%	0.54	2.55[1.68, 3.41]	P<0.00001*
SPARCC spine score
nr-axSpA	2	187	198	0%	0.47	1.52[1.41,1.63]	P<0.00001*
AS	2	64	64	18%	0.27	7.18[3.92,10.44]	P<0.0001*
ASDAS
nr-axSpA	3	280	295	91%	P<0.0001	0.87[0.58,1.16]	P<0.00001*
BASDAI
nr-axSpA	4	439	453	84%	0.0003	0.85[0.37,1.33]	P = 0.0005*
BASFI
nr-axSpA	4	439	453	71%	0.01	0.90[0.51, 1.28]	P<0.00001*
CRP
nr-axSpA	4	439	453	73%	0.01	2.94[0.21,5.67]	P = 0.03*

Abbreviations: SPARCC, Spondyloarthritis Research Consortium Canada score; SIJ, sacroiliac joints; TNFi, tumor necrosis factor α inhibitor; ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis disease activity index; BASFI, Bath Ankylosing Spondylitis functional index; CRP, C-reactive protein; AS, ankylosing spondylitis; axSpA, axial spondyloarthritis; nr-axSpA, non-radiographic axial spondyloarthritis; MD, mean difference; CI, confidence interval;

*p<0.05.