Cohort characteristics and rates of missing data from 1415 cases in the Yorkshire Early Arthritis Register.
| Categorical Data | n (%) | No. Cases with Missing Data, n (%) |
| Female | 932 (66) | 0 (0) |
| RF-positive | 952 (71) | 82 (6) |
| ACPA-positive | 553 (64) | 553 (39) |
| EMS duration, min | 45 (3) | |
| 0–29 | 271 (20) | |
| 30–59 | 172 (13) | |
| 60–119 | 346 (25) | |
| 120–179 | 236 (17) | |
| ≥ 180 | 345 (25) | |
| Continuous Data | Mean (SD) | No. Cases with Missing Data, n (%) |
| Age, yrs | 57.7 (14.2) | 0 (0) |
| Symptom duration, mos* | 7.1 (4.3) | 0 (0) |
| Pain VAS, cm | 6.1 (2.6) | 90 (6) |
| Fatigue VAS, cm | 5.3 (2.9) | 291 (21) |
| DAS28-CRP, baseline | 5.01 (1.33) | 157 (11) |
| HAQ-DI, baseline | 1.22 (0.57) | 72 (5) |
| DAS28-CRP, 6 mos | 3.64 (1.57) | 449 (32) |
| HAQ-DI, 6 mos | 0.97 (0.64) | 302 (21) |
| DAS28-CRP, 12 mos | 3.22 (1.48) | 413 (29) |
| HAQ-DI, 12 mos | 0.89 (0.63) | 344 (24) |
↵* Cases with missing values for symptom duration were excluded to focus the analysis on outcome in early RA. RF: rheumatoid factor; ACPA: anticitrullinated protein antibodies; EMS: early morning stiffness; VAS: visual analog scale; DAS28-CRP: Disease Activity Score in 28 joints and C-reactive protein; HAQ-DI: Health Assessment Questionnaire-Disability Index.