Table 2.

Multivariate Model of Risk Factors for Stage 2–3 Acute Kidney Injury in the Full Cohort as and Stratified According to Baseline Presence of Stage 1 Acute Kidney Injury

Antibiotic Treatment Groupa	Full Cohort		No AKI at Baseline		Stage 1 AKI at Baseline
	OR (95% CI)b	P Value	OR (95% CI)	P Value	OR (95% CI)b	P Value
PTZ/VAN vs CEF/VAN	1.09 (.83–1.43)	.57	1.41 (.95– 2.04)	.085	0.75 (.50–1.12)	.17
PTZ/VAN vs MER/VAN	1.50 (.78–1.72)	.49	1.22 (.71– 2.08)	.48	0.88 (.48–1.61)	.69

Abbreviations: AKI, acute kidney injury; CEF, cefepime; CI, confidence interval; MER, meropenem; OR, odds ratio; PTZ, piperacillin-tazobactam; VAN, vancomycin.

^aThe reference antibiotic groups for the 2 models are CEF/VAN and MER/VAN, respectively.

^bModel adjusted for the following covariates: age, sex, body mass index, Acute Physiology and Chronic Health Evaluation III score, Charlson Comorbidity Index, creatinine level at antibiotic initiation, creatinine clearance based on the Cockroft-Gault equation at antibiotic initiation, pH ≤7.3, use of mechanical ventilation, hemoglobin level <9 g/dL, sepsis defined according to Sepsis-3 criteria [24], vasopressor use, and nephrotoxin exposure. Consistent with the methods of Malhotra et al [23], nephrotoxin exposure reflects exposure to amphotericin B, aminoglycosides, iodinated contrast medium, nephrotoxic chemotherapy, nonsteroidal anti-inflammatory drugs (excluding low-dose maintenance aspirin), and nephrotoxic antiretroviral therapy in the 7 days before hospital admission through 48 hours after the index intensive care unit admission.