CRP and spondylitis: Besides, CAR was positively correlated with erythrocyte sedimentation rate (ESR) (r = 0.704, P < 0.001), CRP (r = 0.996, P < 0.001), BASDAI (r = 0.329, P < 0.001), and Bath Ankylosing Spondylitis Functional Index (BASFI) (r = 0.330, P < 0.001).