Table 1

Characteristics of patients with complete information of SI (n=859) at baseline and at the time of SI, compared with the remaining cohort and stratified by outcome of SI

CohortPatients with SI
SI onlySI+sepsisSI+death
At baseline/enrolment
 N11 15067113553
 Age (years)55.7 (12.5)59.0 (11.6)63.8 (10.3)68.2 (7.1)
 Sex (female, n (%))8610 (77.2)493 (73.5)98 (72.6)34 (64.2)
 Symptom onset (years before enrolment)10.1 (9.1)12.2 (9.9)15.1 (11.9)12.4 (10)
 Rheumatoid factor positive, n (%)8026 (72.3)527 (78.5)115 (85.2)44 (83.0)
 CRP (mg/L)18.7 (26.2)25.8 (35.4)31.5 (45.8)30.0 (35.2)
 DAS285.2 (1.3)5.5 (1.3)5.7 (1.2)6.1 (1.3)
Comorbidities: heart failure, n (%)207 (1.9)39 (5.8)19 (14.1)10 (18.9)
 Chronic renal disease, n (%)353 (3.2)57 (8.5)25 (18.5)10 (18.9)
 COPD, n (%)737 (6.6)107 (16.0)23 (17.0)14 (26.4)
 Diabetes, n (%)1024 (9.2)109 (16.2)35 (25.9)15 (28.3)
Smoking (never, n (%))4813 (43.2)290 (43.2)52 (38.5)20 (37.7)
No. of previous bDMARDs
 0, n (%)8371 (75.1)442 (65.9)91 (67.4)44 (83)
 ≥2, n (%)1250 (11.2)107 (15.9)19 (14.1)3 (5.7)
TNFi, n (%)5384 (48.3)356 (53.1)76 (56.3)27 (50.9)
Other bDMARDs, n (%)2203 (19.8)182 (27.1)28 (20.7)8 (15.1)
Glucocorticoids
 <5 mg, n (%)3671 (32.9)156 (23.3)30 (22.2)11 (20.8)
 ≥10 mg, n (%)2256 (20.2)181 (26.8)34 (25.2)14 (26.4)
At the time of first serious infection:
 Age at SI60.8 (11.7)66.0 (10.1)70.5 (7.3)
 CRP mg/L17.4 (26.4)24.3 (36.9)17.0 (23.5)
 DAS284.3 (1.5)4.6 (1.4)4.6 (1.6)
Comorbidities
 Heart failure, n (%)46 (6.9)21 (15.6)19 (35.8)
 Chronic renal disease, n (%)68 (10.1)32 (23.7)14 (26.4)
TNFi, n (%)297 (44.3)44 (32.6)14 (26.4)
Other bDMARDs, n (%)129 (19.2)17 (12.6)3 (5.7)
Glucocorticoids
 <5 mg, n (%)257 (38.3)40 (29.6)16 (30.2)
 ≥10 mg, n (%)100 (14.9)26 (19.3)14 (26.4)
  • Other bDMARD (tocilizumab, rituximab, abatacept). Numbers represent mean (sd) or frequencies (%). Amount of missing data: at baseline most frequent missings were found in CRP (5.0%) and DAS28 (3.1%), at the last study visit prior to SI the CRP was missing in 8.9%.

  • COPD, chronic obstructive pulmonary disease; CRP, C reactive protein; DAS28, disease activity score (28 joint count); DMARD, disease-modifying antirheumatic drug; bDMARD; biologic DMARD; N, number; SI, serious infection; TNFi, tumor necrosis factor-α inhibitors (adalimumab, etanercept, infliximab, golimumab, certolizumab),