Table 2

Multivariate linear regressions analyses of factors associated with ASDAS–CRP, BASDAI, BASFI and HAQ–AS

	ASDAS–CRP			BASDAI			BASFI			HAQ–AS
	Standard coefficient	Regression coefficient (95% CI)	p Value	Standard coefficient	Regression coefficient (95% CI)	p Value	Standard coefficient	Regression coefficient (95% CI)	p Value	Standard coefficient	Regression coefficient (95% CI)	p Value
Smoker	0.09	0.20 (0.02 to 0.38)	0.03	0.12	0.50 (0.17 to 0.83)	0.003	0.08	0.38 (0.07 to 0.69)	0.02	NS	NS	–
Caucasian race	−0.16	−0.55 (−0.83 to −0.27)	<0.001	−0.14	−0.94 (−1.48 to −0.41)	0.001	NS	NS	–	NS	NS	–
Male sex	NI	NI	–	NS	NS	–	−0.08	−0.35 (−0.65 to −0.05)	0.02	−0.23	−0.32 (−0.43 to −0.22)	<0.001
HLA-B27 positivity	−0.10	−0.22 (−0.39 to −0.04)	0.02	−0.13	−0.52 (−0.85 to −0.19)	0.002	NS	NS	–	NS	NS	–
Drinker	−0.09	−0.25 (−0.49 to −0.02)	0.04	NS	NS	–	NS	NS	–	NS	NS	–
CRP	NI	NI	–	0.10	0.16 (0.02 to 0.31)	0.03	NI	NI	–	NI	NI	–
ESR	NI	NI	–	0.16	0.34 (0.13 to 0.55)	0.002	NI	NI	–	NI	NI	–
MRI spine inflammatory lesions	NS	NS	–	NI	NI	–	NS	NS	–	NI	NI	–
MRI sacroiliac joint inflammatory lesions	NI	NI	–	−0.17	−0.70 (−1.04 to −0.36)	<0.001	−0.10	−0.48 (−0.80 to −0.16)	0.04	−0.08	−0.11 (−0.22 to 0.00)	0.04
ASDAS–CRP	NI	NI	–	NI	NI	–	0.54	1.16 (1.02 to 1.30)	<0.001	0.43	0.29 (0.24 to 0.34)	<0.001
BASMI	NI	NI	–	NI	NI	–	0.20	0.51 (0.34 to 0.68)	<0.001	0.14	0.09 (0.04 to 0.13)	<0.001

ASDAS–CRP, ankylosing spondylitis disease activity score, C-reactive protein based; 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; HAQ–AS, health assessment questionnaire for ankylosing spondylitis; HLA, human leucocyte antigen; NI, not included in the multivariate model; NS, non-significant in multivariate analysis.