TABLE 4.

Net Reclassification Improvement for GFR Estimating Equations when Compared to CKD-EPI_cr,cysc Equation

Estimating Equation by Outcome		Category-based* NRI (95% CI)	p-value	Category-free** NRI (95% CI)	p-value
All-Cause Mortality
BIS2	Events	0.37 (0.34, 0.40)	<0.0001	0.81 (0.77, 0.84)	<0.001
	NonEvents	−0.40 (−0.42, −0.38)	<0.0001	−0.94 (−0.95, −0.92)	<0.001
	Total NRI	−0.03 (−0.07, 0.01)	0.312	−0.13 (−0.16, −0.09)	0.002
CKD-EPIcr	Events	−0.24 (−0.28, −0.20)	<0.0001	−0.38 (−0.44, −0.32)	<0.0001
	NonEvents	0.07 (0.05, 0.09)	<0.0001	0.04 (0.004, 0.08)	0.03
	Total NRI	−0.17 (−0.22, −0.13)	<0.0001	−0.34 (−0.41, −0.27)	<0.0001
CKD-EPIcysc	Events	0.23 (0.20, 0.27)	<0.0001	0.53 (0.47, 0.59)	<0.001
	NonEvents	−0.15 (−0.17, −0.13)	<0.0001	−0.24 (−0.28, −0.20)	<0.001
	Total NRI	0.08 (0.04, 0.12)	0.0002	0.29 (0.22, 0.36)	<0.001
Cardiovascular Mortality
BIS2	Events	0.33 (0.28, 0.39)	<0.0001	0.76 (0.69, 0.83)	<0.001
	NonEvents	−0.39 (−0.41, −0.38)	<0.0001	−0.91 (−0.93, −0.90)	<0.001
	Total NRI	−0.06 (−0.12, 0.0004)	0.114	−0.16 (−0.22, −0.09)	0.01
CKD-EPIcr	Events	−0.23 (−0.31, −0.16)	<0.0001	−0.40 (−0.50, −0.29)	<0.0001
	NonEvents	0.10 (0.08, 0.12)	<0.0001	0.10 (0.07, 0.14)	<0.0001
	Total NRI	−0.13 (−0.21, −0.06)	0.0012	−0.29 (−0.40, −0.18)	<0.0001
CKD-EPIcysc	Events	0.24 (0.18, 0.29)	<0.0001	0.52 (0.43, 0.62)	<0.001
	NonEvents	−0.17 (−0.18, −0.15)	<0.0001	−0.29 (−0.33, −0.26)	<0.001
	Total NRI	0.07 (0.01, 0.13)	0.0363	0.23 (0.13, 0.33)	<0.001

Abbreviations: GFR, glomerular filtration rate; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; cr, creatinine; cysc, cystatin c; NRI, net reclassification improvement; CI, confidence interval; BIS, Berlin Initiative Study

^*Based on categorization ≥90, 75–89, 60–74, <60 mL/min/1.73m²

^**Based upon a 1 mL/min/1.73m² change in estimated glomerular filtration rate