Table 6.

Mean difference between sinistrin clearances and estimated GFRs and accuracy within 30% of sinistrin clearance for each segment obtained by applying circular binary segmentation for all bias values (sinistrin clearance − estimated GFR) using combined Schwartz and new combined quadratic formulas

CBS Segments and Corresponding iGFRs (ml/min per 1.73 m2)Mean Difference between iGFRs and eGFRs (ml/min per 1.73 m2)Accuracy within 30% of iGFR (%)
Using combined Schwartz formula
 First segment: iGFRs<75 090
 Second segment: 75≤iGFRs<91995
 Third segment: 91≤iGFRs<1262080
 Fourth segment: iGFRs≥126 NENE
Using new combined quadratic formula
 First segment: iGFRs<81−793
 Second segment: 81≤iGFRs<96 −1100
 Third segment: 96≤iGFRs<126 9100
 Fourth segment: iGFRs≥126 NENE
  • CBS, circular binary segmentation; iGFR, sinistrin clearance; eGFR, estimated GFR; NE, not evaluated (only four observations identified in that CBS segment, precluding any statistical analysis).