Table 3:
Bias, precision and accuracy of eGFR for the CKD-EPI09-NB and CKD-EPI21 equations across CKD stages in the total cohort.
| CKD-EPI09-NB | CKD-EPI21 | |||
|---|---|---|---|---|
| Total cohort | GFR <30 ( N = 196) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | 7.7 (−0.1 to 16.5) | 9.7 (1.2–19.7) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | 11.7 (9.1–14.3) | 13.9 (11.1–16.6) | ||
| Precision, mL/min/1.73 m2 | 16.6 | 18.5 | ||
| Relative bias, %, median (Q1–Q3) | 39.4 (−0.7 to 95.0) | 49.6 (7.2–110.6) | ||
| Relative bias, %, mean (95% CI) | 90.2 (65.0–115.4) | 103.6 (76.6–130.6) | ||
| Accuracy, % (95% CI) | 30.6 (24.5–37.3) | 30.1 (24.0–36.8) | ||
| 30 ≤ GFR < 60 ( N = 811) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | 4.7 (−4.7 to 16.5) | 8.4 (−1.7 to 21.0) | |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | 7.7 (6.5–9.0) | 11.4 (10.1–12.6) | ||
| Precision, mL/min/1.73 m2 | 21.2 | 22.7 | ||
| Relative bias, %, median (Q1–Q3) | 10.0 (−10.5 to 36.5) | 18.3 (−3.7 to 45.9) | ||
| Relative bias, %, mean (95% CI) | 16.4 (13.7–19.0) | 24.2 (21.5–26.9) | ||
| Accuracy, % (95% CI) | 60.4 (57.0–63.7) | 54.7 (51.3–58.2) | ||
| GFR ≥60 ( N = 3681) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −7.8 (−20.9 to 4.7) | −3.3 (−16.5 to 9.2) | |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −8.3 (−8.9 to −7.6) | −4.0 (−4.6 to −3.3) | ||
| Precision, mL/min/1.73 m2 | 25.6 | 25.8 | ||
| Relative bias, %, median (Q1–Q3) | −8.5 (−20.2 to 5.5) | −3.5 (−15.8 to 10.8) | ||
| Relative bias, %, mean (95% CI) | −6.0 (−6.7 to −5.3) | −1.2 (−1.9 to −0.5) | ||
| Accuracy, % (95% CI) | 75 (73–76) | 78 (77–80) | ||
| Cancer cohort | GFR <30 ( N = 78) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | 15.8 (9.1–30.3) | 18.8 (11.4–33.2) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | 20.0 (16.2–23.7) | 22.9 (19.0–26.8) | ||
| Precision, mL/min/1.73 m2 | 21.2 | 21.9 | ||
| Relative bias, %, median (Q1–Q3) | 80.5 (38.1–175.6) | 93.3 (49.3–197.7) | ||
| Relative bias, %, mean (95% CI) | 156.5 (104.4–208.5) | 175.7 (119.5–231.8) | ||
| Accuracy, % (95% CI) | 12 (6–20) | 12 (6–20) | ||
| 30 ≤ GFR < 60 ( N = 508) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | 8.0 (−1.3 to 20.7) | 11.8 (2.2–25.5) | |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | 10.5 (9.0–11.9) | 14.6 (13.1–16.1) | ||
| Precision, mL/min/1.73 m2 | 22.0 | 23.4 | ||
| Relative bias, %, median (Q1–Q3) | 16.6 (−2.8 to 45.1) | 25.9 (4.4–56.0) | ||
| Relative bias, %, mean (95% CI) | 22.4 (19.3–25.5) | 31.0 (27.8–34.2) | ||
| Accuracy, % (95% CI) | 58 (54–63) | 50 (45–54) | ||
| GFR ≥60 ( N = 2727) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −7.1 (−19.8 to 4.9) | −2.7 (−15.3 to 9.5) | |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −7.8 (−8.5 to −7.1) | −3.4 (−4.1 to −2.6) | ||
| Precision, mL/min/1.73 m2 | 24.7 | 24.9 | ||
| Relative bias, %, median (Q1–Q3) | −7.7 (−19.4 to 5.8) | −2.7 (−14.8 to 11.4) | ||
| Relative bias, %, mean (95% CI) | −5.5 (−6.3 to −4.8) | −0.6 (−1.3 to 0.2) | ||
| Accuracy, % (95% CI) | 76 (75–78) | 80 (78–81) | ||
| Kidney donor cohorta | GFR ≥60 ( N = maskedb) |
Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −11.8 (−22.2 to 1.2) | −6.7 (−18.0 to 5.6) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −10.1 (−12.5 to −7.8) | −5.8 (−8.2 to −3.5) | ||
| Precision, mL/min/1.73 m2 | 23.4 | 23.6 | ||
| Relative bias, %, median (Q1–Q3) | −10.9 (−20.4 to 1.4) | −7.1 (−16.9 to 7.1) | ||
| Relative bias, %, mean (95% CI) | −7.7 (−10.0 to −5.4) | −3.3 (−5.7 to −1.0) | ||
| Accuracy, % (95% CI) | 80 (75–85) | 89 (84–92) |
CI, confidence interval.
Absolute bias is calculated as the difference between eGFR and mGFR; relative bias is calculated as the difference between eGFR and mGFR divided by the mGFR; precision is calculated as the IQR of the bias; and the accuracy is calculated as the percentage of patients with eGFR within the range of ±30% of the mGFR (P30).
aWe did not report the results for potential living kidney donors with mGFR <60 mL/min/1.73 m2 because of the low number of these patients.
bCells are masked, so it is not possible to identify or back-calculate numbers less than 5.