Comparison of disease activity, damage score and mortality between damage clusters
| Variables | Cluster 1 (n=824) | Cluster 2 (n=195) | Cluster 3 (n=111) | P value |
|---|---|---|---|---|
| Age at SLE diagnosis | 27.87±10.60 | 27.21±11.31 | 25.56±10.36 | 0.399 |
| Female sex | 774 (93.9)a | 169 (86.7)c | 102 (91.9) | 0.002 |
| Disease duration at last follow up, years | 12.07±5.42ab | 14.96±6.05c | 14.06±5.84c | <0.001 |
| Weighted GRS | 1.56±1.09 | 1.78±1.00 | 1.43±1.12 | 0.036$ |
| Adjusted Mean SLEDAI | 3.96±2.21 | 5.40±2.94 | 4.20±2.94 | <0.001 |
| Mortality | 20 (2.4) | 11 (5.6) | 16 (14.4) | <0.001 |
| Damage involvement (at last follow-up) | ||||
| Ocular | 0 | 113 (58.0) | 16 (14.4) | <0.001 |
| Neuropsychiatric | 0 | 4 (2.1) | 111 (100.0) | <0.001 |
| Renal | 0 | 108 (55.4) | 11 (9.9) | <0.001 |
| Pulmonary | 60 (7.3) | 20 (10.3) | 19 (17.1) | 0.002 |
| Cardiovascular | 26 (3.2) | 13 (6.7) | 3 (2.7) | 0.055 |
| Peripheral vascular | 27 (3.3) | 8 (4.1) | 5 (4.5) | 0.722 |
| Gastrointestinal | 8 (1.0) | 3 (1.5) | 3 (2.7) | 0.024 |
| Musculoskeletal | 132 (16.0) | 57 (29.2) | 39 (35.1) | <0.001 |
| Skin | 31 (3.8) | 10 (5.1) | 7 (6.3) | 0.367 |
| Premature gonadal failure | 0 | 5 (2.6) | 4 (3.6) | <0.001 |
| Diabetes Mellitus | 22 (2.7) | 16 (8.2) | 6 (5.4) | 0.001 |
| Malignancy | 47 (5.7) | 7 (3.6) | 3 (2.7) | 0.237 |
aSignificantly different from cluster 2.
bSignificantly different from cluster 3.
cSignificantly different from cluster 1.
*Continuous variables were compared using analysis of variance (ANOVA) and nominal variable (mortality) was compares using chi-square test.
$Tukey’s test showed there was no statistically significant difference between clusters.