CRP and spondylitis: JAK: Janus kinase; N: number; SD: standard deviation; RF: rheumatoid factor; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; DAS28: Disease Activity Score-28; ASDAS: Ankylosing Spondylitis Disease Activity Score; DAPSA: Disease Activity Index for Psoriatic Arthritis