Characteristics and demography of the participants at baseline.
| Characteristics | Percentage of Participants with Missing Data | csDMARD | bDMARD | p | bDMARD | ||
|---|---|---|---|---|---|---|---|
| IA | IB | II | |||||
| Overall, n (%) | 33 (34) | 63 (66) | 20 | 22 | 21 | ||
| Female, n (%) | 0 | 21 (64) | 41 (65) | 0.94 | 14 (70) | 13 (59) | 14 (67) |
| Age, yrs, median (range) | 0 | 59 (23–82) | 62 (32–82) | 0.57 | 62 (32–73) | 59 (38–75) | 64 (46–82) |
| Education > high school, n (%) | 5.2 | 10 (30) | 20 (32) | 0.91 | 5 (25) | 8 (38) | 7 (33) |
| Disease duration, yrs, median (range) | 0 | 7 (0–54) | 12 (0.5–33) | 0.02 | 11 (3–33) | 14 (5–32) | 15 (0.5–30) |
| HAQ, median (range) | 3.1 | 0.625 (0–2.125) | 0.375 (0–2.875) | 0.29 | 1 (0–2.875) | 0.9 (0–1.75) | 0.75 (0–2.125) |
| DAS28, median (range) | 4.2 | 2.6 (1.4–5.9) | 2.3 (1.0–6.1) | 0.42 | 2.4 (1.3–5.8) | 2.4 (1–5.1) | 2.2 (1.3–6.1) |
| CRP, median (range) | 4.2 | 5 (1–37) | 2 (0–36) | 0.05 | 3 (1–19) | 2 (0–36) | 2 (0–13) |
| Smoker, n (%) | 0 | 8 (24) | 17 (27) | 0.90 | 4 (20) | 8 (36) | 5 (24) |
| Ex-smoker, n (%) | 0 | 15 (45) | 29 (46) | 0.95 | 8 (40) | 9 (41) | 12 (57) |
| Pack yrs, median (range) | 0 | 25 (1–60) | 16 (1–55) | 0.34 | 18.5 (2–50) | 20 (3–55) | 15 (1–50) |
| Alcohol ≥ 7 units/week, n (%) | 0 | 8 (13) | 5 (15) | 0.74 | 2 (10) | 4 (18) | 2 (10) |
| Comorbidities, mean | 0 | 2.15 | 2.14 | 0.95 | 2.1 | 2.1 | 2.2 |
| Current treatment | |||||||
| Anti–TNF-α, n (%) | 0 | 37 (59) | 14 (70) | 11 (50) | 12 (57) | ||
| Anti–IL-6, n (%) | 0 | 9 (14) | 2 (10) | 4 (18) | 3 (14) | ||
| RTX, n (%)* | 0 | 4 (6) | 1 (5) | 1 (5) | 2 (10) | ||
| CTLA-4, n (%) | 0 | 13 (21) | 3 (15) | 6 (27) | 4 (19) | ||
| MTX, n (%) | 0 | 30 (91) | 43 (68) | 15 (75) | 15 (68) | 13 (62) | |
| Prednisolone treatment, n (%) | 0 | 4 (12) | 12 (19) | 2 (10) | 4 (17) | 6 (29) | |
| Prednisolone dose, mg/day, mean | 0 | 5.8 | 5.8 | 8.8 | 4.1 | 7.3 | |
| Anti–TNF-α treatment, mos, mean | 0 | 60.9 | 61.3 | 59.7 | 61.5 | ||
| Anti–IL-6 treatment, mos, mean | 0 | 15.2 | 23.6 | 15.8 | 8.9 | ||
| RTX treatment, mos, mean | 0 | 55.3 | 106 | 64.9 | 20.6 | ||
| CTLA-4 treatment, mos, mean | 0 | 11.7 | 5.2 | 17.0 | 8.7 | ||
| MTX treatment, mos, mean | 0 | 52.6 | 73.4 | 80.2 | 64.7 | 76.0 | |
| Prior treatment | |||||||
| No. prior bDMARD treatments, median (range) | 0 | 0 (0–3) | 1 (0–5) | 0.5 (0–4) | 1 (0–5) | 1 (0–5) | |
| Prior bDMARD treatment, mos, mean | 5.7# | 28.5 | 22.3 | 26.6 | 19.9 | 23.7 | |
| Prior csDMARD treatment, mos, mean | 30.6# | 28.3 | 27.4 | 19.7 | 30.6 | 23.5 | |
| Overall treatment, mos, mean | 25.2# | 28.3 | 23.9 | 22.0 | 25.4 | 23.6 | |
↵* RTX was administered 15–146 days prior to vaccination with the 13-valent protein conjugated pneumococcal vaccine.
↵# Treatment history of csDMARD and bDMARD are comprehensive only with starting and ending dates from January 2006, and hence duration is missing for earlier exposure. DMARD: disease-modifying antirheumatic drug; csDMARD: conventional synthetic DMARD; bDMARD: biological DMARD; HAQ: Health Assessment Questionnaire; DAS28: Disease Activity Score at 28 joints; CRP: C-reactive protein; Pack yr: 1 pack-year = 20 cigarettes daily for 1 year; anti-TNF-α: anti-tumour necrosis factor-α; IL-6: interleukin 6; RTX: rituximab, anti-CD20 inhibitor; CTLA-4: abatacept, T cell lymphocyte costimulation inhibitor; MTX: methotrexate.