A potential pitfall in the use of the Disease Activity Score (DAS28) as the main response criterion in treatment guidelines for patients with rheumatoid arthritis. Issue 3 (11th February 2005) - Gardiner, P V; Bell, A L; Taggart, A J; Wright, G; Kee, F; Smyth, A; McKane, R; Lee, J; Rooney, M E; Whitehead, E