. Author manuscript; available in PMC: 2015 Apr 1.

Published in final edited form as: Hepatology. 2013 Sep 30;59(4):1532–1542. doi: 10.1002/hep.26556

Table 4. Bias, Precision and Accuracy of CKD-EPI Creatinine-Cystatin C Equation (2012) in Subjects with Cirrhosis Stratified by Type of Ascites.

	Pre-Ascites	Diuretic-Sensitive Ascites	Diuretic-Refractory Ascites	P Value^†
Bias	10.67	−1.11	−5.09	0.058
Precision^*	28.28	15.36	22.59	0.154
Accuracy (1-P₃₀)^*	24.00	11.11	40.00	0.075
Accuracy (1-P₂₀)^*	36.00	44.44	55.00	0.444
Accuracy (RMSE)^*	30.23	15.41	23.16	0.141

mGFR=GFR measured by non-radiolabeled iothalamate plasma clearance (gold standard)

eGFR=Estimated GFR

Difference score (DS)=mGFR-eGFR (or the differences between mGFR and CrCl, or between mGFR and CrCl estimated by CG equation) for each subject

Bias=Mean DS

Precision=Standard deviation of DS

Accuracy=Percentage of eGFRs that differed by greater than 30% (1-P₃₀) or 20% (1-P₂₀) of mGFRs or root mean square error (RMSE)

Lower values for precision and accuracy [(1-P₃₀), (1-P₂₀) and RMSE] indicate higher precision and accuracy for CrCl, CG and GFR-estimating equations

^†

P values compare the performance of CKD-EPI creatinine-cystatin C (2012) among subjects with pre-ascites, diuretic-sensitive and -refractory ascites. Note the low P-value for bias does not reflect a difference in magnitude of bias, but rather reflects (in this case) a difference in the direction of bias.