TABLE 3.
Accuracy and precision for intraday and interday runsa
| Antibiotic | Concn (μg/ml) (QC level) | n | Intraday runs |
Interday runs |
||
|---|---|---|---|---|---|---|
| Bias (%) | CV (%) | Bias (%) | CV (%) | |||
| Cefepime | 0.500 (QC LLOQ) | 18 | −6.1 to 19.4 | 6.0 to 7.8 | 10.9 | 12.8 |
| 1.50 (QC low) | 18 | −9.0 to −2.9 | 6.6 to 8.1 | −6.6 | 7.6 | |
| 75.0 (QC medium) | 18 | −3.6 to 12.6 | 2.0 to 3.2 | 4.0 | 7.0 | |
| 120 (QC high) | 18 | −13.6 to −2.5 | 4.2 to 5.1 | −6.5 | 7.0 | |
| Meropenem | 0.100 (QC LLOQ) | 18 | −12.4 to 18.3 | 8.3 to 17.5 | 5.6 | 18.9 |
| 0.300 (QC low) | 18 | 3.3 to 11.3 | 5.3 to 10.1 | 8.4 | 8.5 | |
| 75.0 (QC medium) | 18 | −9.8 to −5.5 | 2.9 to 4.4 | −8.2 | 4.0 | |
| 120 (QC high) | 18 | −14.2 to −4.6 | 6.4 to 8.5 | −8.0 | 7.8 | |
| Piperacillin | 0.100 (QC LLOQ) | 18 | −2.5 to 15.3 | 6.1 to 11.0 | 4.5 | 10.8 |
| 0.300 (QC low) | 16b | 8.8 to 10.8 | 7.8 to 14.6 | 10.0 | 11.7 | |
| 75.0 (QC medium) | 18 | −10.2 to −5.0 | 4.9 to 7.9 | −7.1 | 7.0 | |
| 120 (QC high) | 18 | −10.6 to −3.6 | 3.8 to 7.2 | −6.1 | 6.2 | |
| Tazobactam | 0.250 (QC LLOQ) | 18 | −4.9 to 10.1 | 4.2 to 12.0 | 1.3 | 9.6 |
| 0.750 (QC low) | 18 | 2.7 to 14.3 | 6.3 to 8.1 | 9.9 | 8.4 | |
| 75.0 (QC medium) | 18 | −2.0 to 10.1 | 4.9 to 9.4 | 5.8 | 8.3 | |
| 120 (QC high) | 18 | −0.7 to 9.7 | 6.5 to 11.4 | 5.8 | 9.8 | |
a
Intraday accuracy and precision were evaluated on three different days, with six samples for each QC level on each day. Interday accuracy and precision were assessed by using the results from these three intraday runs.
b
Outliers were excluded.