European multicentre evaluation of the analytical performance of the Abbott AxSYM Abused Drugs Assays.

In accordance with the guidelines of the European Committee for Clinical Laboratory Standards (ECCLS), the performance of the Abbott AxSYM Abused Drugs assays were evaluated and compared with the results provided by the following systems: Syva Emit d.a.u./Roche Cobas Mira S Plus, Abbott TDx and ADx, Syva Emit d.a.u./Syva ETS Plus, Syva Emit II/Hitachi 717 and Roche Abuscreen OnLine/Roche Cobas Mira S Plus. The test analytes, cannabinoids, cocaine metabolites, opiates, benzodiazepines and barbiturates, were each investigated in three laboratories on different systems. The imprecision of all systems in the series and from day to day was good, with CVs less than 5% or 10%, respectively. The AxSYM calibration curves were stable for 3-4 months and none of the systems displayed any shift in the results of the analyses within one day or any faults caused by sample contamination. Within the framework of this study, a total of 1860 urine samples were investigated; 741 results were positive. All results which remained discrepant between AxSYM and the comparison systems after repeated analysis (n = 17) were subjected to further investigation using a reference method, with the exception of one barbiturate and two benzodiazepine samples. An additional test criterion was the practicability of the systems investigated and the versatility of the software. During this evaluation, the results provided by the Abbott AxSYM were excellent and were fully in line with the manufacturer's claims. The reliability of the FPIA technology that has been the subject of frequent investigation was also convincing during this evaluation. The possibility of semi-quantitative determination, the stability of the calibration curves, the ability to process an emergency sample without delay and its high suitability to routine operations are the convincing benefits offered by this system.