Table 1

Variables at baseline, pre-PSM and post-PSM for patients with 5 years of follow-up

VariableBias pre-PSMBias post-PSM
Belimumab (n=195)SoC (n=372)Bias (%)*Belimumab (n=99)SoC (n=99)Bias (%)*
Mean age, years42.837.345.540.039.08.4
Mean age squared, years1947.41560.838.11733.01661.77.2
Female, %92.889.511.692.991.93.8
Black, %23.115.319.721.223.2−4.8
Asian†/other race, %9.223.4−
Mean SLE duration, years7.95.830.07.47.6−2.6
Smoker, %3.623.7−
Hypertension‡, %67.737.663.054.553.52.0
Dyslipidaemia, %22.658.1−77.528.331.3−6.6
Proteinuria, %12.331.7−
Number of ACR classification criteria satisfied5.95.719.
Baseline SLEDAI7.810.1−−2.2
Corticosteroid use, %63.660.85.864.666.7−4.2
Antimalarial use, %73.851.946.669.768.72.2
Immunosuppressive use, %53.831.546.445.544.42.0
SDI score=1, %27.214.830.724.227.3−6.9
SDI score ≥2, %28.710.846.215.218.2−8.1
  • *The extent of balance in clinical characteristics between groups was assessed using a standardised distance (bias) for each of the variables in the PS model. The standardised distance in the PS-matched sample across groups for all variables used to determine PS values ideally should be <5%; however, a standardised distance of <10% for all variables is considered adequate balance.

  • †Asian from the BLISS LTE population refers to patients with Central Asian, East Asian, Japanese, South Asian and Southeast Asian heritage; and Asian from the TLC refers to patients of Chinese heritage.

  • ‡Patients who met any of the following criteria at baseline were defined as having hypertension: (1) systolic blood pressure ≥140 mm Hg or (2) diastolic pressure ≥90 mm Hg or (3) use of antihypertensive medications. The BLISS database had a flag for patients with baseline hypertension, but any BLISS patients who were not flagged were defined as having hypertension based on the same criteria used for TLC patients.

  • ACR, American College of Rheumatology; PS, propensity score; PSM, propensity score matching; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SLE, systemic lupus erythematosus; SLEDAI, SLE Disease Activity Index; SoC, standard of care; TLC, Toronto Lupus Cohort.