Table 1

Sample description and group comparisons

Potential predictorsTotalSerious infectionP value*
N=1459Absent
N=1434
Present
N=25
Sociodemographic variables
Age (visit 1)49.1±13.548.9±13.356.6±18.20.030
Female sex1315 (90.4%)1292 (90.4%)23 (92.0%)1.000
Ethnicity
Caucasian1327 (93.8%)1304 (93.9%)23 (92.0%)0.407
Latin-American64 (4.5%)63 (4.5%)1 (4.0%)
Other23 (1.6%)22 (1.6%)1 (4.0%)
Smoking
Never652 (48.9%)641 (49.0%)11 (45.8%)0.065
Ever or current smoker680 (51.1%)667 (51.0%)13 (54.2%)
Clinical features and comorbidities
Charlson comorbidity index2.5±1.82.5±1.83.9±2.70.004
Diabetes50 (3.5%)48 (3.4%)2 (8.3%)0.200
Malignancy40 (2.8%)39 (2.7%)1 (4.2%)0.493
Chronic kidney disease148 (10.6%)141 (10.3%)7 (30.4%)0.002
SLE activity (SLEDAI)2.7±3.82.7±3.83.2±5.70.918
Damage (SDI)1.4±1.81.4±1.82.8±2.20.0005
Katz severity index4.4±2.04.4±1.95.7±1.80.0004
SLE-related hospitalisation354 (25.4%)334 (24.4%)20 (83.3%)<0.0001
Previous serious infection88 (6.1%)77 (5.4%)11 (45.8%)<0.0001
Laboratory results
Creatinine1.03±1.821.03±1.831.15±0.710.468
Lymphopenia (<1000/mm3)272 (18.8%)266 (18.7%)6 (25.0%)0.436
Hypocomplementemia540 (37.5%)531 (37.5%)9 (37.5%)1.000
Treatments
Maximum GC dose0.044
≤5 mg526 (67.1%)518 (67.6%)8 (44.4%)
>5 mg and<10 mg116 (14.8%)112 (14.6%)4 (22.2%)
≥10 mg and<30 mg100 (12.8%)97 (12.7%)3 (16.7%)
≥30 mg29 (3.7%)26 (3.4%)3 (16.7%)
Methylprednisolone pulse13 (1.7%)13 (1.7%)
Antimalarials802 (55.0%)791 (55.2%)11 (44.0%)0.266
Cyclophosphamide12 (0.8%)10 (0.7%)2 (8.0%)0.017
Mycophenolate114 (7.8%)109 (7.6%)5 (20.0%)0.022
Rituximab45 (3.1%)44 (3.1%)1 (4.0%)0.546
Other (MTX or azathioprine)215 (14.7%)212 (14.8%)3 (12.0%)1.000
  • *P values for absent versus present comparisons. Statistically significant variables are highlighted in bold.

  • GC, glucocorticoid; MTX, methotrexate; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index; SLE, systemic lupus erythematosus; SLEDAI, SLE Activity Index.