Univariable and multivariable Cox regression analyses: predictors of CKD among the clinical characteristics at 12 months
| Univariable analysis | Multivariable analysis | |||||
| HR | 95% CI | P value | HR | 95% CI | P value | |
| Failure to achieve EULAR/ERA-EDTA response at 1 year | 5.604 | 3.228 to 9.728 | <0.0001 | 5.165 | 2.770 to 7.628 | <0.0001 |
| Year of LN diagnosis | 0.976 | 0.953 to 1.000 | 0.053 | |||
| Serum creatinine, mg/dL* | 1.485 | 1.276 to 1.625 | <0.0001 | – | – | – |
| Serum creatinine, difference from baseline to 1 year | 1.484 | 1.208 to 1.823 | 0.0015 | – | – | – |
| eGFR, mL/min/1.73 m2† | 0.967 | 0.957 to 0.977 | <0.0001 | – | – | – |
| eGFR, difference from baseline to 1 year | 1.002 | 0.995 to 1.009 | 0.645 | – | – | – |
| Proteinuria, g/day‡ | 1.234 | 1.111 to 1.370 | <0.0001 | – | – | – |
| Proteinuria, difference from baseline to 1 year | 1.033 | 0.947 to 1.128 | 0.462 | – | – | – |
| Urinary erythrocytes | 1.005 | 0.098 to 1.028 | 0.310 | – | – | – |
| Erythrocyte difference from baseline to 1 year | 1.006 | 0.992 to 1.029 | 0.421 | – | – | – |
| Arterial hypertension | 3.522 | 1.835 to 6.878 | 0.0013 | 3.154 | 1.500 to 4.547 | <0.013 |
| C3, mg/dL | 0.999 | 0.977 to 1.001 | 0.077 | – | – | – |
| C3 mg/dL, difference from baseline to 1 year | 0.989 | 0.978 to 0.997 | 0.013 | – | – | – |
| C4, mg/dL§ | 1.049 | 1.015 to 1.084 | 0.004 | 1.053 | 1.019 to 1.089 | 0.0014 |
| C4 mg/dL, difference from baseline to 1 year | 1.004 | 0.974 to 1.035 | 0.784 | |||
Out of 381 patients, 53 developed CKD.
Schoenfeld residuals analysis confirmed the proportional hazard hypothesis.
*HR for any mg/dL increase in serum creatinine.
†HR for any mL/min/1.73 m2 decrease in eGFR.
‡HR for any g/day increase in proteinuria.
§HR for any mg/dL decrease in C4 value.
CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; EULAR/ERA-EDTA, European League Against Rheumatism/European Renal Association-European Dialysis and Transplant Association; LN, lupus nephritis.