Baseline demographic characteristics of cases of rheumatoid arthritis (RA) and controls in MyEIRA, by ethnicity.

<p>RF: rheumatoid factor, ACPA: anti-citrullinated proteins antibody, SE: shared epitope.</p><p>*patients and controls carrying one or two alleles of shared epitope were classified as SE-positive.</p><p>The percentages calculated in each characteristic category were based on the number of available data.</p>