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Table 3 Multilevel analysis of factors associated with hospital mortality

From: The clinical relevance of oliguria in the critically ill patient: analysis of a large observational database

VariablesOR (95% CI)p value
Fixed effects, varying within clusters
 Age1.00 (1.00–1.01)0.19
 Sex, male0.99 (0.85–1.14)0.848
 SAPS II1.05 (1.05–1.06)< 0.001
 Type of admission (%)
  SurgicalRefna
  Medical1.53 (1.26–1.86)< 0.001
  Trauma1.53 (1.14–2.05)0.004
  Other1.92 (0.71–5.17)0.196
 Source of admission
  OR/recoveryRefna
  Other hospital1.17 (0.81–1.68)0.404
  ER/ambulance1.12 (0.84–1.49)0.458
  Hospital floor1.65 (1.26–2.16)< 0.001
  Other1.20 (0.81–1.80)0.366
 Comorbidities
  COPD0.98 (0.73–1.31)0.877
  Cancer1.41 (1.15–1.74)0.001
  Metastatic cancer1.20 (0.86–1.67)0.281
  Hematologic cancer1.75 (1.25–2.44)0.001
  Insulin0.84 (0.64–1.09)0.189
  Heart failure, NYHA III/IV1.54 (1.19–1.99)0.001
  HIV infection0.73 (0.27–1.94)0.523
  Cirrhosis2.12 (1.45–3.10)< 0.001
  Immunosuppression1.19 (0.78–1.79)0.419
  Steroid therapy1.17 (0.74–1.84)0.497
  Chemotherapy0.92 (0.55–1.53)0.748
 Creatinine, highest [mg/dl]1.00 (0.97–1.02)0.796
 Daily fluid balancea [l]1.37 (1.25–1.50)< 0.001
 Procedures during the ICU stay
  Mechanical ventilation2.66 (2.12–3.34)< 0.001
  Renal replacement therapy1.51 (1.19–1.91)0.001
 Severity of sepsis
  No sepsisRefna
  Sepsis without shock0.98 (0.75–1.28)0.887
  Septic shock1.55 (1.25–1.92)< 0.001
 End-of-life decision11.82 (6.70–20.84)< 0.001
 Oliguria on admission1.14 (0.97–1.34)0.103
Fixed effects, constant within clusters
 Type of hospital  
  University/academicRefna
  Non-university1.16 (0.88–1.52)0.293
 Number of patients admitted to the ICU (in 2011)
  750+Refna
  500–7490.95 (0.76–1.19)0.663
  250–4990.95 (0.68–1.31)0.746
  < 2501.21 (0.77–1.91)0.415
 ICU specialty
  SurgicalRefna
  Medical0.63 (0.38–1.04)0.072
  Mixed0.73 (0.54–1.00)0.047
  Others0.94 (0.58–1.52)0.79
 Staffed ICU beds
  15+Refna
  < 151.12 (0.87–1.44)0.397
 Income
  HighRefna
  Upper middle1.81 (1.20–2.73)0.005
  Low and lower middle2.05 (1.37–3.08)0.001
Random effects
 Country
  Variance (se)0.23 (0.08) 
p value0.004 
 Hospital within country
  Variance (se)0.50 (0.09) 
p value< 0.001 
  1. aTotal fluid balance divided by the length of ICU stay
  2. OR odds ratio, SAPS II Simplified Acute Physiology Score II, ER emergency room, OR operating room, COPD chronic obstructive pulmonary disease, NYHA New York Heart Association, HIV human immunodeficiency virus. The percentage of cases correctly classified with this model is 88.6%. The AUC is 91.5% (95% CI 90.7–92.3%)