Table 5: Net reclassification improvement (NRI) for GFR estimating equations.

Estimating equation by outcomeCategory-basedCategory-free
NRI (95% CI) valueNRI (95% CI)-value

All-cause mortality
BIS1 (compared to reference CKD-)
 Events0.63 (0.60, 0.67)<0.0010.91 (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-)
 Events0.46 (0.42, 0.50)<0.0010.85 (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-)
 Events0.62 (0.56, 0.68)<0.0010.89 (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-)
 Events0.43 (0.36, 0.50)<0.0010.80 (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.