Characteristics of the study population of Swedish women with rheumatoid arthritis (RA) (biologics-naive and starting a first ever tumour necrosis factor inhibitor (TNFi) treatment 1999–2012, respectively), and matched general population comparator subjects
| Characteristics at start of follow-up | TNFi initiators | Biologics-naive RA | General female population |
|---|---|---|---|
| n | 9629 | 34 984 | 300 331 |
| Age at entry (median, min–max) | 56 (18–92) | 62 (18–97) | 61 (18–96) |
| Year of birth (median, min–max) | 1949 (1907–1994) | 1943 (1906–1994) | 1944 (1906–1994) |
| Year of entry (median, min–max) | 2006 (1999–2012) | 2004 (2001–2012) | 2004 (2001–2012) |
| Time since RA onset (years) | 8.2 | NA | NA |
| DAS28 (median, IQR) at biologics start | 5.30 (4.40–6.13) | NA | NA |
| HAQ (median, IQR) at biologics start | 1.25 (0.88–1.75) | NA | NA |
| Concomitant DMARDs (%) | 71 | NA | NA |
| Concomitant oral steroids (%) | 47 | NA | NA |
| Educational level, years (%) | |||
| ≤9 | 25 | 36 | 33 |
| 9–12 | 44 | 40 | 40 |
| >12 | 31 | 22 | 26 |
| Comorbidities (%) | |||
| Chronic obstructive pulmonary disease | 2.4 | 3.3 | 1.9 |
| Diabetes mellitus | 5.2 | 5.8 | 4.2 |
| Ischaemic heart disease | 4.2 | 7.8 | 5.7 |
| Previous joint surgery | 27.8 | 20.4 | 5.2 |
| Total n days spent in hospital during last five years, median (IQR) | 1 (0–10) | 1 (0–9) | 0 (0–2) |
| Cervical screening characteristics, all individuals | |||
| Mean n cervical screens during last five years preceding start of follow-up (range) | 1.17 (0–12) | 0.89 (0–15) | 0.91 (0–19) |
| Median time since last cervical screening visit at date of start of follow-up (days, range) | 825 (1–6198) | 937 (1–7718) | 895 (1–16 626) |
| CIN 1 within five years before start of FU (%) | 0.5 | 0.4 | 0.3 |
| CIN 2+ within five years before start of FU (%) | 0.7 | 0.5 | 0.4 |
| Mean number of cervical screens during follow-up, (range) | 1.08 (0–19) | 0.65 (0–18) | 0.87 (0–24) |
| Cervical screening characteristics, individuals below 60 years of age at baseline | |||
| Mean n cervical screens during last five years preceding start of follow-up (range) | 1.44 (0–12) | 1.39 (0–15) | 1.39 (0–19) |
| Median time since last cervical screening visit at date of start of follow-up (days, range) | 655 (1–6198) | 686 (1–6476) | 676 (1–6520) |
| CIN 1 within five years before start of follow-up (%) | 0.7 | 0.7 | 0.5 |
| CIN 2+ within five years before start of follow-up (%) | 1.0 | 1.0 | 0.8 |
| Mean number of cervical screens during follow-up, (range) | 1.56 (0–19) | 1.23 (0–18) | 1.60 (0–24) |
CIN, cervical intraepithelial neoplasia; DAS28, disease activity score 28; DMARD, disease-modifying antirheumatic drug; FU, follow-up; HAQ, health assessment questionnaire; NA, not available.