Renal Function and Death in Older Women: Which eGFR Formula Should We Use?

Table 5

Net reclassification improvement (NRI) for GFR estimating equations.

Estimating equation by outcome	Category-based		Category-free
	NRI (95% CI)	value	NRI (95% CI)	-value
All-cause mortality
BIS1 (compared to reference CKD-)
Events	0.63 (0.60, 0.67)	<0.001	0.91 (0.88, 0.94)	<0.001
Nonevents	−0.64 (−0.68, −0.61)	<0.001	−0.96 (−0.98, −0.95)	<0.001
Total NRI	−0.01 (−0.06, 0.04)	0.815	−0.05 (−0.09, −0.02)	0.336
BIS2 (compared to reference CKD-)
Events	0.46 (0.42, 0.50)	<0.001	0.85 (0.82, 0.89)	<0.001
Nonevents	−0.47 (−0.51, −0.44)	<0.001	−0.94 (−0.96, −0.92)	<0.001
Total NRI	−0.02 (−0.07, 0.04)	0.655	−0.09 (−0.13, −0.05)	0.108
Cardiovascular mortality
BIS1 (compared to reference CKD-)
Events	0.62 (0.56, 0.68)	<0.001	0.89 (0.84, 0.95)	<0.001
Nonevents	−0.64 (−0.67, −0.61)	<0.001	−0.95 (−0.96, −0.93)	<0.001
Total NRI	−0.02 (−0.09, 0.05)	0.682	−0.05 (−0.11, 0.004)	0.459
BIS2 (compared to reference CKD-)
Events	0.43 (0.36, 0.50)	<0.001	0.80 (0.74, 0.87)	<0.001
Nonevents	−0.47 (−0.50, −0.44)	<0.001	−0.91 (−0.94, −0.89)	<0.001
Total NRI	−0.04 (−0.11, 0.03)	0.394	−0.11 (−0.18, −0.05)	0.097

GFR, glomerular filtration rate; NRI, net reclassification improvement; BIS, Berlin Initiative Study; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; cr, creatinine; cysc, cystatin C.
Based on categorization ≥75, 60 to <75, 45 to <60, <45 mL/min/1.73 m².
NRI, total = NRI, events + NRI, nonevents
NRI, events = [proportion of participants reclassified downward to a lower eGFR category for people who died MINUS proportion of participants reclassified upward for people who died]
NRI, nonevents = [proportion of participants reclassified upward to a higher eGFR category for people who did not die MINUS the proportion of participants reclassified downward for people who did not die].
Based upon a 1 mL/min/1.73 m² change in estimated glomerular filtration rate.