Table 3.

Intention-to-treat Cox proportional hazards model of associations between key covariates and time to all-cause mortality

CovariateUnivariable Analysis, Derivation CohortParsimonious Multivariable Model, Derivation CohortShort Multivariable Model, Derivation Cohort
HR (95% CI)P ValueHR (95% CI)P Value HR (95% CI)P Value
Demographics
 Age (per 10 yr)1.05 (0.99–1.12)0.081.11 (1.04–1.19)0.003
 Male sex1.19 (0.99–1.43)0.06
 Black (versus other races)0.70 (0.55–0.89)0.0030.81 (0.63–1.03)0.09
Hospital location
 Surgical service (versus medical service)0.51 (0.42–0.61)<0.0010.39 (0.32–0.47)<0.0010.36 (0.30–0.43)<0.001
 ICU (versus other hospital location)4.39 (3.70–5.21)<0.0012.07 (1.69–2.53)<0.0012.97 (2.46–3.59)<0.001
Comorbidities (present at admission)
 HIV0.87 (0.36–2.09)0.75
 Congestive heart failure0.93 (0.77–1.12)0.450.80 (0.65–0.99)0.04
 Diabetes0.75 (0.59–0.94)0.01
 Liver disease1.90 (1.56–2.32)<0.0011.48 (1.21–1.81)<0.001
 Malignancy1.91 (1.47–2.48)<0.0011.31 (0.99–1.73)0.06
 Metastatic solid tumor2.64 (2.06–3.40)<0.0012.18 (1.67–2.84)<0.0012.79 (2.16–3.61)<0.001
 Myocardial infarction1.13 (0.87–1.48)0.35
 Peptic ulcer disease1.23 (0.71–2.12)0.46
 Peripheral vascular disease1.02 (0.78–1.33)0.91
 Pulmonary disease0.95 (0.92–0.99)0.02
Laboratory values
 Baseline creatinine (per 0.1 mg/dl)1.04 (1.00–1.08)0.05
 Bicarbonate (per mEq/L)0.88 (0.86–0.89)<0.0010.95 (0.93–0.97)<0.001
 BUN (per 10 mg/dl)1.18 (1.16–1.21)<0.0011.14 (1.10–1.18)<0.0011.12 (1.09–1.15)<0.001
 Change in creatinine from day prior (per 0.1 mg/dl)1.06 (1.05–1.07)<0.0011.05 (1.04–1.06)<0.0011.05 (1.04–1.05)<0.001
 Creatinine (per mg/dl)1.31 (1.24–1.39)<0.0010.81 (0.73–0.90)<0.001
 Potassium (per mEq/L)1.70 (1.57–1.83)<0.0011.16 (1.06–1.26)0.001
Medications
 Number of sedatives (per drug)1.69 (1.59–1.79)<0.001
 Prior aminoglycoside exposure0.92 (0.74–1.13)0.420.77 (0.61–0.96)0.01
 Number of antibiotics (per drug)1.42 (1.36–1.48)<0.0011.08 (1.02–1.14)0.01
 Number of pressors (per drug)1.83 (1.72–1.94)<0.0011.38 (1.26–1.50)<0.0011.55 (1.43–1.67)<0.001
 Paralytic exposure4.60 (3.64–5.80)<0.0011.95 (1.53–2.50)<0.001
 Thiazide diuretic0.67 (0.52–0.87)0.0020.60 (0.47–0.78)<0.001
Other orders
 Ventilated3.65 (3.12–4.27)<0.0011.43 (1.20–1.70)<0.001
  • n=35,028 patient-days, 3901 patients, and 778 outcome events. Data were censored at 14 days from the onset of AKI or August 31, 2010, whichever came first. Data excludes patient-days after initiation of dialysis or placement of a do not resuscitate order. HR, hazard ratio; CI, confidence interval; ICU, intensive care unit.