Demographic and clinical characteristics of the Spanish patients with RA included in the study.

RA: Rheumatoid arthritis; SD: Standard deviation; Anti-CCP antibodies: Anti-cyclic citrullinated peptide antibodies.*At least two determinations were required for analysis of this result.** Extra-articular manifestations of the disease (if RA patients experienced at least one of the following manifestations: nodular disease, Felty’s syndrome, pulmonary fibrosis, rheumatoid vasculitis, or secondary Sjögren’s syndrome) [2].***At the time of assessment.Demographic and clinical characteristics of the Spanish patients with RA included in the study.