Table 1.
Characteristics of participants by flare status
| Flare classification |
|||||||
|---|---|---|---|---|---|---|---|
| Patient (n=849) |
MD (n=718) |
DAS28 (n=515) |
|||||
| Variable mean (SD) or n (%) unless otherwise stated | All (n=849) | Yes (n=201) | No (n=648) | Yes (n=233) | No (n=485) | Yes (n=84) | No (n=431) |
| Sociodemographic characteristics | |||||||
| Age (years) | 54.3 (15.4) | 53.7 (14.3) | 54.4 (15.7) | 54.9 (15.0) | 53.6 (15.4) | 55.0 (15.5) | 54.7 (14.5) |
| Female sex | 635 (75%) | 149 (74%) | 486 (75%) | 168 (72%) | 365 (75%) | 61 (73%) | 308 (71%) |
| White | 690 (81%) | 154 (77%) | 536 (83%) | 181 (78%) | 385 (79%) | 69 (82%) | 357 (83%) |
| Education ≤ high school | 342 (40%) | 95 (47%) | 247 (38%) | 104 (45%) | 172 (35%) | 32 (38%) | 174 (40%) |
| Currently smoking ≤ 2 years | 140 (17%) | 39 (20%) | 101 (16%) | 37 (16%) | 81 (17%) | 17 (20%) | 60 (14%) |
| Duration in study (months; median IQR) | 18 (15) | 18 (15) | 18 (15) | 12 (18) | 18 (12) | 21 (12) | 18 (15) |
| RA characteristics | |||||||
| DAS28 | 3.2 (1.6) | 3.7 (1.7) | 3.0 (1.5) | 3.9 (1.7) | 2.7 (1.4) | 2.8 (1.2) | 3.2 (1.7) |
| Remission | 277 (44%) | 44 (30%) | 233 (49%) | 55 (30%) | 182 (51%) | 40 (48%) | 199 (46%) |
| Low | 83 (13%) | 14 (10%) | 69 (14%) | 16 (9%) | 59 (17%) | 20 (24%) | 49 (11%) |
| Moderate | 182 (29%) | 57 (39%) | 125 (26%) | 68 (37%) | 91 (26%) | 21 (25%) | 120 (28%) |
| High | 82 (13%) | 30 (21%) | 52 (11%) | 44 (24%) | 23 (6%) | 3 (4%) | 63 (15%) |
| MD tender joints (28) | 3.2 (5.0) | 4.9 (5.8) | 2.7 (4.6) | 5.4 (6.2) | 2.2 (3.9) | 2.1 (3.7) | 3.7 (5.6) |
| MD swollen joints (28) | 2.2 (4.1) | 3.2 (4.7) | 1.9 (3.9) | 4.1 (5.5) | 1.2 (2.6) | 1.5 (3.6) | 2.7 (4.8) |
| ESR (mm/h) | 17.2 (17.4) | 18.4 (18.1) | 16.8 (17.2) | 21.0 (20.0) | 15.4 (16.1) | 19.3 (20.6) | 16.7 (16.7) |
| CRP (mg/L) | 6.5 (10.5) | 8.3 (12.8) | 6.0 (9.6) | 8.6 (11.8) | 5.3 (8.8) | 7.7 (11.2) | 6.1 (9.0) |
| HAQ (0–3) | 0.51 (0.60) | 0.75 (0.67) | 0.44 (0.55) | 0.66 (0.63) | 0.42 (0.56) | 0.47 (0.59) | 0.49 (0.60) |
| MD global (10 cm VAS) | 1.9 (2.5) | 2.8 (2.9) | 1.6 (2.3) | 3.2 (2.9) | 1.2 (1.9) | 1.3 (1.8) | 2.0 (2.6) |
| Patient global (10 cm VAS) | 3.4 (2.9) | 4.6 (3.1) | 3.0 (2.8) | 4.2 (3.0) | 2.9 (2.8) | 2.7 (2.7) | 3.4 (3.0) |
| Pain (10 cm VAS) | 3.2 (2.8) | 4.3 (3.0) | 2.8 (2.6) | 4.0 (2.9) | 2.7 (2.7) | 2.8 (2.7) | 3.2 (2.9) |
Sociodemographic characteristics are at enrolment; RA characteristics are at first of paired visits. At second visit, 718 patients had a second MD rating of flare and 515 had a DAS28-ESR at both visits; missing DAS28 values are due to missing ESR.
CRP, C reactive protein; DAS, Disease Activity Score; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; RA, rheumatoid arthritis; VAS, Visual Analogue Scale.