For all-cause mortality , there was no improvement in the reclassification of eGFR categories using the CKD-EPI-cystatin C ( NRI -4.1 % ; p = 0.401 ) and CKD-EPI-creatinine-cystatin C ( NRI -1.2 % ; p = 0.748 ) compared with CKD-EPI-creatinine equation .