Baseline characteristics of the study cohort
| Baseline characteristics | All patients (N=2199) | SELENA-SLEDAI <6 (N=1643) | SELENA-SLEDAI ≥6 (N=528) |
|---|---|---|---|
| Mean age, years | 32.9 | 33.8 | 30.1 |
| Mean age at cohort entry, years | 38.0 | 39.0 | 35.2 |
| Gender, n (%) | |||
| Male | 165 (7.50) | 126 (7.67) | 37 (7.01) |
| Female | 2034 (92.50) | 1517 (92.33) | 491 (92.99) |
| Race, n (%) | |||
| White | 1215 (55.25) | 965 (58.73) | 232 (43.94) |
| Black | 827 (37.61) | 558 (33.96) | 261 (49.43) |
| Asian | 74 (3.37) | 58 (3.53) | 15 (2.84) |
| Other | 83 (3.77) | 62 (3.77) | 20 (3.79) |
| Mean SDI score at cohort entry | 1.2 | 1.1 | 1.3 |
| Mean SELENA-SLEDAI score at cohort entry | 3.5 | 1.7 | 9.2 |
| Prednisone use at cohort entry, n (%)* | |||
| Yes | 1144 (52.72) | 755 (46.04) | 387 (73.30) |
| No | 1026 (47.28) | 885 (53.96) | 141 (26.70) |
| Year of SLE diagnosis, n (%) | |||
| Pre-1980s | 143 (6.50) | 98 (5.96) | 44 (8.33) |
| 1980s | 408 (18.55) | 270 (16.43) | 134 (25.38) |
| 1990s | 826 (37.56) | 621 (37.80) | 190 (35.98) |
| 2000s | 822 (37.38) | 654 (39.80) | 160 (30.30) |
| Time since SLE diagnosis | |||
| Mean, years | 5.1 | 5.2 | 5.1 |
| <1, n (%) | 642 (29.20) | 478 (29.09) | 154 (29.17) |
| 1–5, n (%) | 831 (37.79) | 641 (39.01) | 179 (33.90) |
| >5, n (%) | 726 (33.02) | 524 (31.89) | 195 (36.93) |
| Follow-up, years, (n %) | |||
| <1 | 489 (22.24) | 374 (22.76) | 111 (21.02) |
| 1–5 | 687 (31.24) | 530 (32.26) | 151 (28.60) |
| 5–10 | 489 (22.24) | 374 (22.76) | 103 (19.51) |
| >10 | 534 (24.28) | 365 (22.22) | 163 (30.87) |
| Mean follow-up, years | 6.2 | 5.9 | 7.2 |
| Mean dropout rate per year, % | 16.1 | 17.1 | 13.9 |
*Data were not available for all 2199 patients.
SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index; SLE, systemic lupus erythematosus.