The new Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry: Design, rationale, and characteristics of patients enrolled in the first 12months

Background Herein we describe the history, design, and rationale of the new Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry and present the characteristics of patients with juvenile idiopathic arthritis (JIA) enrolled in the first 12 months of operation.