Table 2.
Intention-to-treat Cox proportional hazards model of associations between key covariates and time to initiation of dialytic therapy
| Covariate | Univariable Analysis, Derivation Cohort | Parsimonious Multivariable Model, Derivation Cohort | Short Multivariable Model, Derivation Cohort | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | P Value | HR (95% CI) | P Value | HR (95% CI) | P Value | |
| Demographics | ||||||
| Age (per 10 yr) | 0.96 (0.90–1.02) | 0.20 | ||||
| Male sex | 1.52 (1.20–1.92) | 0.001 | ||||
| Black (versus other races) | 0.53 (0.39–0.74) | <0.001 | 0.63 (0.46–0.86) | 0.004 | ||
| Hospital location | ||||||
| Surgical service (versusmedical service) | 1.05 (0.83–1.33) | 0.66 | 0.70 (0.55–0.90) | 0.01 | ||
| ICU (versus other hospital location) | 5.68 (4.55–7.09) | <0.001 | 1.93 (1.52–2.45) | <0.001 | 2.98 (2.35–3.78) | <0.001 |
| Comorbidities (present at admission) | ||||||
| HIV | 0.15 (0.03–0.76) | 0.02 | ||||
| Congestive heart failure | 1.19 (0.95–1.50) | 0.13 | ||||
| Diabetes | 1.06 (0.82–1.37) | 0.64 | 1.27 (1.00–1.62) | 0.05 | ||
| Liver disease | 3.70 (2.95–4.63) | <0.001 | 2.45 (1.94–3.09) | <0.001 | 2.75 (2.18–3.47) | <0.001 |
| Malignancy | 0.72 (0.46–1.11) | 0.14 | ||||
| Metastatic solid tumor | 0.86 (0.53–1.42) | 0.56 | ||||
| Myocardial infarction | 1.13 (0.82–1.55) | 0.46 | ||||
| Peptic ulcer disease | 2.15 (1.32–3.50) | 0.002 | ||||
| Peripheral vascular disease | 1.10 (0.81–1.49) | 0.54 | ||||
| Pulmonary disease | 0.73 (0.45–1.20) | 0.22 | ||||
| Laboratory values | ||||||
| Baseline creatinine (per 0.1 mg/dl) | 1.19 (1.14–1.24) | <0.001 | ||||
| Bicarbonate (per mEq/L) | 0.86 (0.84–0.88) | <0.001 | 0.95 (0.93–0.98) | <0.001 | ||
| BUN (per 10 mg/dl) | 1.27 (1.24–1.30) | <0.001 | 1.07 (1.03–1.10) | <0.001 | ||
| Change in creatinine from day prior (per 0.1 mg/dl) | 1.09 (1.08–1.11) | <0.001 | 1.02 (1.02–1.03) | <0.001 | 1.02 (1.01–1.03) | <0.001 |
| Creatinine (per mg/dl) | 1.86 (1.75–1.99) | <0.001 | 1.53 (1.41–1.67) | <0.001 | 1.64 (1.54–1.76) | <0.001 |
| Potassium (per mEq/L) | 2.08 (1.94–2.23) | <0.001 | 1.27 (1.16–1.40) | <0.001 | 1.35 (1.23–1.48) | <0.001 |
| Medications | ||||||
| Number of sedatives (per drug) | 1.81 (1.68–1.94) | <0.001 | 1.14 (1.04–1.26) | 0.01 | ||
| Prior aminoglycoside exposure | 1.20 (0.95–1.53) | 0.13 | ||||
| Number of antibiotics (per drug) | 1.42 (1.35–1.49) | <0.001 | 1.12 (1.06–1.19) | <0.001 | ||
| Number of pressors (per drug) | 2.12 (1.98–2.26) | <0.001 | 1.28 (1.18–1.40) | <0.001 | 1.44 (1.33–1.55) | <0.001 |
| Paralytic exposure | 4.55 (3.50–5.92) | <0.001 | 1.40 (1.03–1.90) | 0.03 | ||
| Thiazide diuretic | 2.25 (1.83–2.76) | <0.001 | 1.63 (1.33–2.00) | <0.001 | ||
| Other orders | ||||||
| Ventilated | 3.71 (3.07–4.49) | <0.001 | 1.22 (0.99–1.51) | 0.06 | ||
n=35,462 patient-days, 3951 patients, and 471 outcome events. Data were censored at discharge, death, or 14 days from the onset of AKI, whichever came first. Data excludes patient-days after placement of a do not resuscitate order. HR, hazard ratio; CI, confidence interval; ICU, intensive care unit.