Cohort characteristics
| *Based on 1959 results. | ||
| †From inflammatory polyarthritis onset to baseline assessment. | ||
| ‡From inflammatory polyarthritis onset to end of follow up. | ||
| ACR, American College of Rheumatology; DMARD, disease modifying antirheumatic drug; RF, rheumatoid factor. | ||
| Age at onset of rheumatoid arthritis (years) (mean (SD)) | 55.6 (16.1) | |
| Female sex (n (%)) | 1408 (67) | |
| Delay from onset to start of follow up (months) (median) | 12 | |
| Cumulative ACR criteria at fifth assessment positive (n (%)) | 1237 (59) | |
| Ever RF positive (n (%)) | 681 (35)* | |
| Used DMARD ever (n (%)) | 986 (47) | |
| Used methotrexate ever (n (%)) | 582 (28) | |
| Disease duration† at baseline (months) | ||
| 1st quartile | 12 | |
| Median | 12 | |
| 3rd quartile | 34.5 | |
| Maximum | 60 | |
| Duration‡ of follow up (years) (mean (SD)) | 7.4 (2.3) | |