Table 1.
Baseline characteristics of the study cohorts of Swedish patients with RA, by treatment status
| Cohort | TNFi | Rituximab | Abatacept | Tocilizumab | JAKi | B/tsDMARD-naïve | General population |
|---|---|---|---|---|---|---|---|
| Individuals (n) | 21 365 | 4123 | 3306 | 2689 | 1289 | 58 233 | 109 532 |
| Observations (n) | 33 609 | 4367 | 3558 | 2895 | 1435 | 58 233 | 215 592 |
| Age, mean (SD) | 56 (46–65) | 62 (52–70) | 60 (50–68) | 58 (47–66) | 59 (49–69) | 63 (52–73) | 57 (46–65) |
| Male (%) | 23% | 23% | 19% | 20% | 18% | 30% | 22% |
| Cohort entry median (IQR) | 2011 (2006–2015) | 2012 (2009–2015) | 2014 (2012–2016) | 2014 (2012–2016) | 2018 (2017–2018) | 2009 (2006–2014) | 2012 (2008–2016) |
| Years of follow-up, median (IQR)a | 6.6 (3.1–10.9) | 5.4 (2.7–8.4) | 3.8 (1.9–5.8) | 3.9 (2.1–6.5) | 0.7 (0.3–1.1) | 6.6 (3.3–10.9) | 5.9 (2.7–10.0) |
| Educational level (%) | |||||||
| Below 9 years (%) | 24% | 27% | 23% | 22% | 19% | 35% | 21% |
| 10–12 years (%) | 47% | 47% | 49% | 48% | 50% | 43% | 45% |
| >12 years (%) | 30% | 26% | 28% | 30% | 32% | 22% | 34% |
| Smoker (%) | 54% | 62% | 57% | 55% | 62% | DU | DU |
| Comorbidities (%)b | |||||||
| Joint replacement surgery (%) | 14% | 20% | 19% | 18% | 20% | 12% | 3% |
| Diabetes mellitus (%) | 6% | 10% | 10% | 8% | 9% | 7% | 4% |
| Hypertension (%) | 15% | 25% | 25% | 21% | 27% | 18% | 10% |
| IHD (%) | 6% | 10% | 10% | 7% | 9% | 9% | 4% |
| CHD (%) | 2% | 4% | 5% | 3% | 4% | 4% | 1% |
| COPD (%) | 3% | 6% | 6% | 4% | 6% | 4% | 2% |
| Renal insufficiency (%) | 1% | 2% | 2% | 2% | 2% | 1% | 1% |
| Disease duration, median (IQR) | 9 (3–17) | 12 (6–21) | 12 (6–21) | 11 (5–19) | 13 (7–22) | 1 (0–7) | NA |
| HAQ median (IQR) | 1.1 (0.8–1.6) | 1.3 (0.9–1.9) | 1.3 (0.9–1.8) | 1.3 (0.9–1.8) | 1.3 (0.8–1.8) | DU | NA |
| DAS28-CRP median (IQR) | 4.7 (3.9–5.5) | 4.8 (4.0–5.6) | 4.7 (3.9–5.4) | 4.8 (4.1–5.6) | 4.5 (3.7–5.2) | DU | NA |
| Tender joint count median (IQR) | 6 (3–10) | 6 (3–11) | 6 (3–10) | 7 (3–12) | 6 (3–10) | DU | NA |
| Swollen joint count median (IQR) | 6 (3–10) | 6 (3–10) | 5 (2–8) | 6 (3–10) | 4 (2–7) | DU | NA |
| ESR (mm/h) | 22 (11–40) | 28 (14–46) | 23 (11–40) | 26 (12–46) | 20 (10–35) | DU | NA |
| CRP (mg/dl) | 10 (4–26) | 12 (5–30) | 8 (3–22) | 11 (4–29) | 5 (2–16) | DU | NA |
| RF-positive RA (%) | 77% | 88% | 79% | 78% | 77% | 69% | NA |
| VAS pain median (IQR) | 60 (40–75) | 61 (42–77) | 65 (45–78) | 65 (46–79) | 63 (42–78) | DU | NA |
| VAS patient global median (IQR) | 60 (40–76) | 62 (43–78) | 65 (47–79) | 65 (46–79) | 64 (45–78) | DU | NA |
| VAS physician global median (IQR) | 40 (25–50) | 40 (30–60) | 45 (30–60) | 50 (34–60) | 40 (30–50) | DU | NA |
| MTX (%) | 62% | 53% | 51% | 48% | 37% | 50% | 0% |
| Non-MTX csDMARDs (%) | 21% | 22% | 16% | 14% | 14% | 14% | 0% |
| CSs (%) | 56% | 70% | 67% | 66% | 64% | 43% | 1% |
| Disability pension (%) | 2% | 2% | 2% | 2% | 2% | 1% | 1% |
| Sick-leave (%) | 18% | 14% | 17% | 18% | 17% | 10% | 8% |
Extended information on baseline characteristics in Supplementary Table S15, available at Rheumatology online.
Follow-up calculated as time from treatment start, until end of follow-up on 31 December 2018, migration date, death date or diagnosis of another rheumatic disease, whichever occurred first.
Co-morbidities, registered up to 5 years before start of follow-up. RA disease characteristics at start of b/tsDMARD median (IQR).
COPD: chronic obstructive pulmonary disease; IHD: ischaemic heart disease; CHD: coronary heart disease; csDMARD: conventional synthetic DMARD; TNFi: TNF inhibitor; NA: not applicable; DU: data unavailable; IQR: interquartile range; VAS: visual analogue scale.