Four hour creatinine clearance is better than plasma creatinine for monitoring renal function in critically ill patients

Table 4 Risk reclassification using creatinine clearance plus clinical predictors (plasma creatinine, urine output, and APACHE II) compared with the clinical model alone for AKI on entry.

	Known baseline creatinine cohort, pCr ≤ 1.24 mg/dl (n= 111)
Comparison of model performance
IDI_AKI	0.22 (0.09 to 0.38)
IDI_No-AKI	0.074 (0.029 to 0.13)
IDI	0.29 (0.12 to 0.49)
NRI_AKI	23 (-9.2 to 56)
NRI_No-AKI	60 (34 to 76)
NRI	83 (29 to 125)
Increase in AUC	0.23 (0.015 to 0.41)
Combined CCl and clinical predictors model performance
AUC	0.77 (0.66 to 0.88)
IS	0.45 (0.29 to 0.61)
IP	0.16 (0.099 to 0.25)
PPV at < 48.6 ml/min	0.88 (0.81 to 0.94)
NPV at < 48.6 ml/min	0.65 (0.46 to 0.85)
Cut-point (ml/min) for PPV > 90%	< 78
Cut-point (ml/min) for NPV > 90%	< 38.7

Values in brackets represent 95% confidence intervals. APACHE: acute physiology and chronic health evaluation; IDI: integrated discrimination improvement; NRI: net reclassification improvement (continuous/category free); AUC: Area under the receiver operator characteristic curve (ideally = 1); Increase in AUC: difference in AUC between the combined model and the clinical predictors only model; CCl: creatinine clearance; IS: integrated sensitivity (ideally = 1); IP: integrated 1-specificity (ideally = 0); PPV: positive predictive value; NPV: negative predictive value.

ISSN: 1364-8535