Mean bias of participants of the accuracy-based creatinine proficiency testing program for creatinine
| Year-round | Specimen name | No. of participants | Target value of creatinine (mg/dL) | Bias | |
|---|---|---|---|---|---|
| Mean±SD (mg/dL) | Mean±SD (%) | ||||
| All data | |||||
| 2022-1st | CAC-22-01 | 1,687 | 0.84 | 0.045±0.314 | 5.4±37.4 |
| CAC-22-02 | 1,687 | 1.36 | 0.002±0.104 | 0.2±7.7 | |
| CAC-22-03 | 1,687 | 1.82 | –0.003±0.149 | –0.2±8.2 | |
| 2022-2nd | CAC-22-04 | 1,706 | 0.99 | 0.032±0.382 | 3.2±38.5 |
| CAC-22-05 | 1,706 | 1.44 | 0.010±0.588 | 0.7±40.9 | |
| CAC-22-06 | 1,706 | 2.00 | –0.013±0.127 | –0.6±6.3 | |
| Without outliers |
|||||
| 2022-1st | CAC-22-01 | 1,596 | 0.84 | 0.024±0.072 | 2.8±8.6 |
| CAC-22-02 | 1,608 | 1.36 | 0.000±0.076 | 0.0±5.6 | |
| CAC-22-03 | 1,591 | 1.82 | 0.003±0.084 | 0.1±4.6 | |
| 2022-2nd | CAC-22-04 | 1,615 | 0.99 | 0.012±0.065 | 1.2±6.5 |
| CAC-22-05 | 1,644 | 1.44 | –0.004±0.074 | –0.3±5.1 | |
| CAC-22-06 | 1,599 | 2.00 | –0.007±0.087 | –0.3±4.4 | |
Abbreviations: 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.