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.