Association of HDAS with longitudinal SLE outcomes
| Longitudinal parameter | Descriptive statistics by HDAS Number (column %) | Association of ever experiencing HDAS with longitudinal SLE outcome* OR (95% CI; p value) | |
| HDAS (n=161) | No HDAS (n=125) | ||
| AMS in highest quartile (AMS ≥4.3) | 9 (5.6) | 59 (47.2) | 11.7 (5.1 to 26.6; <0.001)† |
| SFI flare occurrence | |||
| No of mild/moderate flares in highest quartile (≥7) | 9 (5.6) | 60 (48.0) | 17.3 (7.4 to 40.5; <0.001) |
| No of severe flares in highest quartile (≥3) | 6 (3.7) | 50 (40.0) | 14.9 (6.0 to 36.9; <0.001) |
| SDI damage accrual | |||
| Accrued damage during observation period | 45 (28.0) | 66 (52.8) | 2.3 (1.3 to 3.9; 0.003) |
| Within a specific organ system | |||
| Musculoskeletal | 16 (9.9) | 23 (18.4) | 1.4 (0.7 to 2.9; 0.365) |
| Skin | 8 (5.0) | 18 (14.4) | 2.4 (1.0 to 6.0; 0.053) |
| Neuropsychiatric | 5 (3.1) | 10 (8.0) | 2.2 (0.7 to 6.8; 0.170) |
| Ocular | 8 (5.0) | 8 (6.4) | 1.1 (0.4 to 3.1; 0.879) |
| Cardiovascular | 11 (6.8) | 10 (8.0) | 0.8 (0.3 to 2.0; 0.617) |
| Renal | 4 (2.5) | 20 (16.0) | 7.2 (2.4 to 22.0; 0.001) |
| Peripheral vascular | 6 (3.7) | 9 (7.2) | 1.4 (0.4 to 4.1; 0.593) |
| Pulmonary | 2 (1.2) | 6 (4.8) | 3.0 (0.6 to 15.5; 0.199) |
| Gastrointestinal | 2 (1.2) | 4 (3.2) | 2.4 (0.4 to 13.6; 0.336) |
| Other | 8 (5.0) | 10 (8.0) | 1.4 (0.5 to 3.7; 0.530) |
| Immunomodulatory drug doses: cumulative dose over observation period in highest quartile‡ | |||
| Prednisolone | 14 (8.7) | 57 (45.6) | 7.7 (3.9 to 15.3; <0.001) |
| Hydroxychloroquine | 31 (19.3) | 40 (32.0) | 0.9 (0.4 to 2.0; 0.819) |
| Methotrexate | 35 (21.7) | 31 (24.8) | 1.1 (0.6 to 1.9; 0.798) |
| Azathioprine/6-mercaptopurine | 30 (18.6) | 41 (32.8) | 1.7 (0.9 to 3.0; 0.076) |
| Mycophenolate | 13 (8.1) | 58 (46.4) | 9.4 (4.8 to 18.5; <0.001) |
*Adjusted for patient observation time. Reference category for OR: those who did not experience HDAS during the observation period.
†OR also adjusted for cumulative prednisolone dose.
‡Limited to immunomodulatory medication taken by ≥10% of patients. Cut-offs for cumulative doses within the highest quartile were prednisolone ≥13.9 g, hydroxychloroquine ≥805.7 g, methotrexate ≥44.9 mg, azathioprine/6-mercaptopurine ≥49.9 g and mycophenolate ≥889.0 g.
AMS, adjusted mean Systemic Lupus Erythematosus Disease Activity Index; HDAS, high disease activity status; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SFI, SELENA flare index.