Table 2.

Bias, precision, and accuracy of new CER estimation equations in the internal and external validation data sets

Number of ParticipantsDifference (mg/day)cPercent DifferencecAccuracy
Median (95% CI)IQRMedian (95% CI)IQRP15 (95% CI)P20 (95% CI)P30 (95% CI)RMSE (95% CI)
Internal validation data set
    equation Da822−6.3 (−27.9, 15.3)326−0.40 (−2.0, 1.2)2659 (56, 62)70 (67, 73)85 (82, 87)303 (284, 321)
    equation Eb658−9.7 (−36.8, 17.3)323−0.60 (−2.7, 1.5)2659 (55, 62)71 (68, 75)86 (84, 89)289 (267, 309)
External validation data set
    equation Da987−10 (−31.9, 12.0)403−0.70 (−2.5, 1.0)3251 (47, 54)62 (59, 65)79 (76, 81)357 (331, 382)
    equation Eb4173.6 (−30.7, 38.0)3620.30 (−2.6, 3.1)2754 (50, 59)63 (59, 68)81 (77, 85)339 (295, 378)
  • CI, confidence interval; IQR, interquartile range.

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