Annual Report on External Quality Assessment in Therapeutic Drug Monitoring in Korea (2005) / 임상검사와정도관리

ABSTRACT

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2005. The number of participating laboratories were increased to 95, by 6.7% comparing with the previous year. Response rates were 100.0% for both trials just like the two previous years. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.7 per institution, which was elevated slightly from 6.5 in recent 5 years. The most common test items were digoxin, valproic acid, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 65% of participating laboratories, followed by cyclosporine, lithium, vancomycin, tacrolimus, methotrexate, amikacin, gentamycin, tobramycin, salicylate, primidone, acetaminophen, free phenytoin, amitryptyline, and ethosuximide. The most widely used TDM analyzer was Abbott TDx/TDxFLx (41.7%), followed by Abbott AxSym (23.3%), and Roche Cobas Integra (19.2%). The inter-laboratory coefficients of variations were not much improved comparing with previous years. We also determined cyclosporine with reference method using liquid chromatography-tandem mass spectrometry. In conclusion, the TDM external quality assessment of 2005 showed grossly similar pattern comparing with those of previous year with increasing participating laboratories.