Study population characteristics
| Subjects characteristic | Entire IP cohort (n = 1098) | HAQ scores at baseline and year 1(followed-up to first year) (n = 1010) | RA subgroup (satisfy ACR criteria by fifth year and followed-up to first year) (n = 698) |
|---|---|---|---|
| ACR, American College of Rheumatology; DAS28, Disease Activity score 28; DMARD, disease-modifying anti-rheumatic drug; HAQ, Health Assessment Questionnaire; IP, inflammatory polyarthritis; IQR, interquartile range; RA, rheumatoid arthritis; RF, rheumatoid factor. | |||
| *HAQ score at baseline obtained from 1086 subjects. | |||
| †HAQ score at year 1 obtained from 1022 subjects. | |||
| ‡Joint counts at year 1 obtained on 1023 subjects. | |||
| §RF measured on 958 subjects. | |||
| ¶DAS28 score obtained on 846 patients. | |||
| **Hospital attendance obtained on 1069 patients. | |||
| Median (IQR) age at symptom onset | 54 (41–66) | 54 (42–66) | 56 (45–68) |
| Female, n (%) | 715 (65.1) | 665 (65.8) | 460 (65.9) |
| Median (IQR) symptom duration at registration (months) | 4 (2–10) | 4 (2–10) | 50 (2–10) |
| Median (IQR) HAQ at baseline* | 0.75 (0.25–1.375) | 0.75 (0.25–1.375) | 1 (0.5–1.625) |
| Median (IQR) HAQ at year 1† | 0.5 (0.125–1.25) | 0.5 (0.125–1.25) | 0.8 (0.25–1.5) |
| Mean (SD) change in HAQ from baseline to year 1 | −0.12 (0.6) | −0.12 (0.6) | −0.14 (0.7) |
| Median (IQR) swollen and tender joint count at baseline | 3 (0–8) | 3 (1–8) | 5 (2–11) |
| Median (IQR) swollen and tender joint count at year 1‡ | 1 (0–3) | 1 (0–3) | 2 (0–5) |
| RF-positive (RF titre ⩾1:80) at baseline, n (%)§ | 218 (22.8) | 204 (22.9) | 185 (29.8) |
| Mean (SD) DAS28 score at baseline¶ | 4 (1.4) | 4.03 (1.4) | 4.5 (1.3) |
| Satisfy ACR criteria at baseline, n (%) | 499 (45.5) | 464 (45.9) | 464 (45.9) |
| Satisfy ACR criteria by fifth year, n (%) | 739 (67.3) | 698 (69.1) | 698 (100) |
| Treated with DMARDs by first year, n (%) | 481 (43.8) | 463 (45.8) | 403 (57.7) |
| Attended hospital by first year, n (%)** | 810 (75.8) | 749 (74.5) | 573 (82.2) |