Association between existing JSN, clinical synovitis, and treatment, and JE onset in joints overall. (A) Ever swelling from 26 through 52 weeks and presence of joint space narrowing (JSN) at week 26 were independent predictors of presence of joint erosion (JE) at 52 weeks. (B) Effect of treatment on the development of JE at 52 weeks in joints with similar characteristics. (C) Association between ever swelling from 26 through 52 weeks and presence of JSN at week 26, and presence of JE at 52 weeks, by treatment group. MTX, methotrexate; ADA, adalimumab.