Mean bias of participants of the accuracy-based creatinine proficiency testing program based on the eGFR
| Year-round | Specimen name | eGFR | ||||||
|---|---|---|---|---|---|---|---|---|
| CKD-EPI | MDRD 4 variable (IDMS-traceable) | |||||||
| No. of participants |
Target value (mL/min/1.73 m2) | Mean bias (%) | No. of participants |
Target value (mL/min/1.73 m2) | Mean bias (%) | |||
| 2020-1st | CAC-20-01 | 88 | 59.9 | –3.6 | 443 | 53.7 | –0.7 | |
| CAC-20-02 | 92 | 29.5 | 3.5 | 427 | 27.7 | 5.3 | ||
| CAC-20-03 | 89 | 10.0 | 3.4 | 429 | 10.5 | 4.5 | ||
| 2020-2nd | CAC-20-04 | 92 | 35.2 | 3.7 | 452 | 31.4 | 4.3 | |
| CAC-20-05 | 98 | 21.4 | 2.6 | 455 | 20.2 | 3.4 | ||
| CAC-20-06 | 90 | 13.5 | 2.9 | 454 | 13.0 | 3.5 | ||
| 2021-1st | CAC-21-01 | 96 | 91.9 | –4.7 | 457 | 78.5 | –3.2 | |
| CAC-21-02 | 97 | 64.1 | –0.3 | 441 | 57.5 | 1.5 | ||
| CAC-21-03 | 93 | 31.6 | –0.6 | 453 | 29.2 | 1.2 | ||
| 2021-2nd | CAC-21-04 | 114 | 89.7 | –3.9 | 433 | 85.8 | –3.1 | |
| CAC-21-05 | 117 | 68.7 | –1.9 | 414 | 62.9 | 0.2 | ||
| CAC-21-06 | 114 | 32.7 | –1.2 | 427 | 30.7 | 0.4 | ||
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; IQR, interquartile range; Q1, 25th percentile; Q3, 75th percentile.
*Number of participants without outlier; The outliers were defined as less than Q1–1.5×IQR or greater than Q3+1.5×IQR and were excluded from analysis.