Variables at baseline, pre-PSM and post-PSM for patients with ≥1 year of follow-up
| Variable | Bias pre-PSM | Bias post-PSM | ||||
| Belimumab (n=259) | SoC (n=706) | Bias (%)* | Belimumab (n=179) | SoC (n=179) | Bias (%)* | |
| Mean age, years | 42.6 | 36.9 | 46.0 | 40.4 | 40.7 | −2.4 |
| Mean age squared, years | 1937.4 | 1541.0 | 37.6 | 1763.4 | 1792.3 | −3.0 |
| Female, % | 93.4 | 88.8 | 16.3 | 91.6 | 91.6 | 0.0 |
| Black, % | 21.6 | 14.6 | 18.3 | 22.3 | 23.5 | −2.7 |
| Asian†/other race, % | 9.3 | 28.0 | −49.6 | 12.8 | 12.8 | 0.0 |
| Mean SLE duration, years | 7.7 | 6.2 | 21.5 | 7.5 | 7.7 | −3.2 |
| Smoker, % | 3.9 | 24.2 | −61.2 | 5.6 | 6.7 | −4.6 |
| Hypertension‡, % | 53.3 | 38.0 | 31.1 | 45.8 | 45.8 | 0.0 |
| Dyslipidaemia, % | 22.8 | 34.7 | −26.5 | 25.1 | 22.9 | 5.2 |
| Proteinuria, % | 13.5 | 33.0 | −47.4 | 16.8 | 17.9 | −2.9 |
| Number of ACR classification criteria satisfied | 6.0 | 5.7 | 22.0 | 6.0 | 5.9 | 1.9 |
| Baseline SLEDAI | 7.9 | 10.0 | −49.0 | 8.4 | 8.5 | −3.7 |
| Corticosteroid use, % | 64.9 | 62.5 | 5.0 | 68.2 | 69.3 | −2.4 |
| Antimalarial use, % | 71.8 | 56.4 | 32.6 | 65.9 | 67.0 | −2.4 |
| Immunosuppressive use, % | 55.2 | 34.4 | 42.7 | 45.8 | 46.4 | −1.1 |
| SDI score=1, % | 27.8 | 14.2 | 33.9 | 24.6 | 25.7 | −2.6 |
| SDI score ≥2, % | 27.8 | 10.2 | 46.0 | 16.8 | 16.8 | 0.0 |
*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.