Table 4.

Comparison of new and existing CER estimation equations in the external validation data set

Number of ParticipantsDifference (mg/day)gPercent DifferencegAccuracy
Median (95% CI)IQRMedian (95% CI)IQRP15 (95% CI)P20 (95% CI)P30 (95% CI)RMSE (95% CI)
Equation Da987−10 (−32, 12)403−0.70 (−2.5, 1.0)3251 (48, 54)62 (59, 65)79 (76, 81)357 (331, 382)
Equation Eb4174 (−31, 38)3620.30 (−2.6, 3.1)2754 (50, 59)63 (59, 68)81 (77, 85)339 (295, 378)
Cockcroft–Gaultc98763 (42, 85)4165.30 (3.7, 7.0)3049 (46, 52)60 (57, 63)76 (74, 79)388 (359, 415)
Walserd987−28 (−52, 5)403−2.20 (−3.9, −0.5)3147 (44, 51)61 (58, 64)78 (75, 80)378 (351, 404)
Goldwassere9875 (−24, 33)4490.50 (−1.7, 2.7)3545 (42, 48)58 (54, 61)76 (74, 79)392 (363, 418)
Rulef98716 (−17, 48)4161.10 (−1.4, 3.6)3346 (43, 49)62 (59, 65)81 (78, 83)357 (330, 381)
  • a Equation D: eCER = 879.89 + 12.51 × weight (kg) − 6.19 × age + (34.51 if black) − (379.42 if female).

  • b Equation E: eCER = 1115.89 + 11.97 × weight (kg) − 5.83 × age − 60.18 × phosphorus (mg/dl) + (52.82 if black) − (368.75 if female).

  • c eCERCockcroft-Gault [ [28 − (0.2 × age)] × weight (kg) × 0.85 if female.

  • d eCERWalser = (28.2 − 0.172 × age) × weight (kg) if male; eCERWalser = (21.9 − 0.115 × age) × weight (kg) if female.

  • e eCERGoldwasser = [23.6 − (age/8.3)(+ 1.9 if black)] × weight (kg).

  • f eCERRule = {exp[7.26 − 0.26 (if female) − (0.011 × (age − 55) if age >55 years)]} × BSA/1.73.

  • g mCER − eCER (positive values indicate that mCER > eCER).