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Table 4 Predictors of 28-day mortality using Cox proportional hazards regression analysis

From: Serum neutrophil gelatinase-associated lipocalin at inception of renal replacement therapy predicts survival in critically ill patients with acute kidney injury

  Univariate   Multivariate  
Variables HR (95% CI) Pvalue HR (95% CI) Pvalue
Age (per 10 years) 0.97 (0.79-1.20) 0.791   
Sex (female) 0.76 (0.40-1.45) 0.401   
SIRS 1.22 (0.48-3.16) 0.675   
Sepsis 3.54 (1.42-8.82) 0.007   
RIFLE category* -- 0.381   
ln SOFA - renal variable (per 1 SD ↑) 1.05 (0.66-1.67) 0.846   
LOS before start of RRT (per day) 1.00 (0.96-1.04) 0.889   
ln APACHE II score (per 1 SD ↑) 1.72 (1.15-2.56) 0.008   
ln total SOFA score (per 1 SD ↑) 1.79 (1.28-2.50) <0.001 1.62 (1.17-2.25) 0.004
ln CRP (per 1 SD ↑) 1.71 (1.13-2.58) 0.012   
ln cystatin C (per 1 SD ↑) 1.07 (0.77-1.50) 0.679   
ln NGAL (per 1 SD ↑) 1.79 (1.28-2.51) <0.001 1.60 (1.15-2.23) 0.005
  1. Estimated hazard ratios (HR), 95% confidence intervals (CI), and P values were calculated by Cox regression analyses (backward elimination). Variables found to be statistical significant at a P value of less than 0.1 in the univariate model were included into the multivariate model using stepwise backward elimination. A two-sided P value of less than 0.05 was considered statistically significant in the multivariate model. Variables that were not normally distributed were log transformed; hazard ratios refer to 1 standard deviation (SD) in the log scale in these variables. † For SIRS and sepsis, the non-SIRS/sepsis group was set as the reference group. *HR (95% CI) for categorical variables is only displayed in case of multivariate significance.
  2. APACHE II score = Acute Physiology And Chronic Health Evaluation score; CRP = C reactive protein; LOS = length of stay in the intensive care unit; NGAL = neutrophil gelatinase-associated lipocalin; RIFLE = a newly developed international consensus classification for acute kidney injury, that defines three grades of severity - risk (class R), injury (class I) and failure (class F); RRT = renal replacement therapy; SOFA = Sequential Organ Failure Assessment score; SIRS = systemic inflammatory response syndrome.