Mean bias of participants of the accuracy-based creatinine proficiency testing program for eGFR
| Year-round | Specimen name | eGFR | ||||||
|---|---|---|---|---|---|---|---|---|
| CKD-EPI | MDRD 4 variable (IDMS-traceable) | |||||||
| No. of participants | Target value (mL/min/1.73 m2) | Mean±SD bias (%) | No. of participants | Target value (mL/min/1.73 m2) | Mean±SD bias (%) | |||
| All data | ||||||||
| 2022-1st | CAC-22-01 | 151 | 75.5 | 2.8±38.8 | 460 | 69.2 | –0.4±11.7 | |
| CAC-22-02 | 151 | 52.3 | 7.7±72.0 | 460 | 51.8 | 1.3±12.5 | ||
| CAC-22-03 | 151 | 30.7 | 12.7±90.9 | 460 | 28.8 | 3.7±28.7 | ||
| 2022-2nd | CAC-22-04 | 163 | 85.4 | 1.4±29.2 | 461 | 78.5 | 0.6±8.9 | |
| CAC-22-05 | 163 | 39.4 | 5.5±42.5 | 461 | 37.1 | 4.3±27.3 | ||
| CAC-22-06 | 163 | 34.0 | 6.4±58.9 | 461 | 33.7 | 4.8±47.5 | ||
| Without outliers |
||||||||
| 2022-1st | CAC-22-01 | 138 | 75.5 | –2.8±7.8 | 440 | 69.2 | –1.3±9.4 | |
| CAC-22-02 | 134 | 52.3 | –0.3±4.5 | 436 | 51.8 | 0.5±6.1 | ||
| CAC-22-03 | 144 | 30.7 | 0.3±5.2 | 438 | 28.8 | 1.2±5.4 | ||
| 2022-2nd | CAC-22-04 | 151 | 85.4 | –0.3±6.0 | 431 | 78.5 | 0.7±6.5 | |
| CAC-22-05 | 145 | 39.4 | 1.4±4.5 | 422 | 37.1 | 2.2±5.1 | ||
| CAC-22-06 | 151 | 34.0 | 1.5±4.0 | 438 | 33.7 | 1.3±4.9 | ||
Abbreviations: eGFR, estimated glomerular filtration rate; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; MDRD, Modification of Diet in Renal Disease; IDMS, Isotope-Dilution Mass Spectrometry; SD, standard deviation; IQR, interquartile range; Q1, 25th percentile; Q3, 75th percentile.
*The outliers were defined as less than Q1–1.5×IQR or greater than Q3+1.5×IQR and were excluded from analysis.