> Boers M; COBRA Study Group. Combinatietherapie Bij Reumatoide Artritis. Demonstration of response in rheumatoid arthritis patients who are nonresponders according to the American College of Rheumatology 20% criteria: the paradox of beneficial treatment effects in nonresponders in the ATTRACT trial. Anti-Tumor Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy. Arthritis Rheum. 2001 Nov;44(11):2703-4. No abstract available.