Evaluation of commercial assays for vancomycin and aminoglycosides in serum: a comparison of accuracy and precision based on external quality assessment.

Objective: To compare the accuracy and precision of commercial assay techniques in the measurement of gentamicin, tobramycin, amikacin, netilmicin and vancomycin in serum.

Methods: Data from the measurement of 40 external quality assessment samples from 358 laboratories providing a therapeutic drug monitoring service were analysed.

Results: Significant differences between techniques in accuracy and precision were observed for all drugs.