CRP and rheumatoid arthritis: The secondary outcomes include the proportions of RA diagnosis, anti-CCP antibody, rheumatoid factor (RF), the high-sensitivity C-reactive protein (hs-CRP), the erythrocyte sedimentation rate (ESR), the 28-tender joint count (TJC28), the 28-swollen joint count (SJC28), morning stiffness time, the visual analog scale (VAS), Patient’s Global Assessment (PtGA), Physician’s Global Assessment (PGA), Health Assessment Questionnaire (HAQ), Generic Quality of Life Inventory-74 (GQOLI-74) scores, and ultrasound images of joints.