Cox regression analyses of the association between demographic and clinical variables at the time of classification with subsequent development of proteinuria of SLE patients (n = 604) with no prior or manifest proteinuria at the time of diagnosis.
| Variables | Univariate Model, HR (95% CI) | p | Combined Model 1*, HR** (95% CI) | p | Combined Model 2*, HR** (95% CI) | p |
|---|---|---|---|---|---|---|
| Male sex | 1.54 (0.98–2.43) | 0.064 | – | – | – | – |
| Age, per decade | 0.83 (0.75–0.93) | 0.001 | 0.84 (0.75–0.94) | 0.002 | 0.84 (0.75–0.93) | 0.002 |
| Age intervals, yrs | ||||||
| ≤ 20 | 2.90 (1.08–8.24) | 0.046 | – | – | – | – |
| 21–40 | 3.18 (1.17–8.70) | 0.023 | – | – | – | – |
| 41–60 | 1.86 (0.66–5.23) | 0.24 | – | – | – | – |
| > 60, ref. | 1 | – | – | – | – | – |
| Malar rash | 0.75 (0.56–1.01) | 0.56 | – | – | – | – |
| Discoid rash | 0.81 (0.51–1.29) | 0.38 | – | – | – | – |
| Photosensitivity | 0.83 (0.61–1.13) | 0.24 | – | – | – | – |
| Oral ulcers | 0.55 (0.31–0.99) | 0.047 | 0.67 (0.37–1.21) | 0.183 | 0.68 (0.37 – 1.22) | 0.193 |
| Arthritis | 1.03 (0.76–1.41) | 0.84 | – | – | – | – |
| Pericarditis | 1.11 (0.74–1.67) | 0.60 | – | – | – | – |
| Pleurisy | 0.97 (0.69–138) | 0.88 | – | – | – | – |
| Psychosis | 1.94 (1.03–3.68) | 0.041 | 2.15 (1.13–4.10) | 0.020 | 2.23 (1.17–4.30) | 0.015 |
| Seizure | 0.76 (0.28–2.05) | 0.59 | – | – | – | – |
| Leukopenia | 1.18 (0.84–1.68) | 0.33 | – | – | – | – |
| Lymphopenia | 1.45 (1.04–1.96) | 0.029 | 1.50 (1.08–2.07) | 0.015 | 1.49 (1.08–2.06) | 0.015 |
| Thrombocytopenia | 1.33 (0.95–1.86) | 0.092 | – | – | – | – |
| Hemolysis | 1.37 (0.82–2.29) | 0.23 | – | – | – | – |
| No. autoantibodies* | 1.25 (1.06–1.46) | 0.008 | – | – | 1.26 (1.06–1.48) | 0.007 |
| No. autoantibodies, intervals | ||||||
| ≤ 1, ref. | 1 | – | – | – | – | – |
| 2 | 1.22 (0.88–1.69) | 0.23 | – | – | – | – |
| 3 | 1.47 (0.89–2.45) | 0.14 | – | – | – | – |
| ≥ 4 | 2.15 (1.09–4.21) | 0.026 | – | – | – | – |
| Anti-dsDNA | 1.36 (1.00–1.83) | 0.047 | 1.38 (1.01–1.87) | 0.042 | – | – |
| Anti-Sm | 1.11 (0.49–2.50) | 0.81 | – | – | – | – |
| IgG or IgM cardiolipin | 1.29 (0.92–1.81) | 0.15 | – | – | – | – |
| LAC | 1.62 (0.76–3.46) | 0.21 | – | – | – | – |
| ANA | 1.75 (0.88–3.45) | 0.11 | – | – | – | – |
| Alopecia | 1.10 (0.70–1.74) | 0.68 | – | – | – | – |
| Positive Coombs test | 1.13 (0.74–1.73) | 0.56 | – | – | – | – |
| Hypertension | 1.40 (0.69–2.83) | 0.36 | – | – | – | – |
| Glucocorticoids | 1.19 (0.88–1.59) | 0.26 | – | – | – | – |
| HCQ | 0.67 (0.50–0.90) | 0.009 | 0.74 (0.55–1.00) | 0.055 | 0.75 (0.58–1.02) | 0.066 |
| Immunosuppressants | 1.31 (0.95–1.80) | 0.06 | – | – | – | – |
Values in bold face are statistically significant.
↵* Adjusted for variables significantly associated in univariate analyses, selecting anti-dsDNA for model 1 and number of autoantibodies for model 2 because of redundant information in these 2 serological variables.
↵** ANA, anti-dsDNA antibodies, anti-Sm antibodies, IgG and/or IgM cardiolipin antibodies and lupus anticoagulant. SLE: systemic lupus erythematosus; ANA: antinuclear antibodies; IgG: immunoglobulin G; LAC: lupus anticoagulant; HCQ: hydroxychloroquine.