Abstract: Objective To analyze the external quality assessment(EQA) program Results for therapeutic drug monitoring (TDM) from 2010 to 2012 in China, and to provide the reference for improving the TDM determination quality .Methods Three times of blood TDM EQA Results and6 times of serum TDM EQA Results from 2010 to 2012 were collected and analyzed statistically by National Center for Clinical Laboratories(NCCL). Results From 2010 to 2011, the number of blood TDM EQA participants increased from 88 to 102, the serum TDM EQA participants increased from 119 to 136. In blood TDM EQA, the average qualified rate of cyclosporine A, tacrolimus, sirolimus in 3 years were 94.2%, 83.4% and 89.1%, respectively. In serum TDM, the average qualified rate of theophylline, digoxin, phenytoin, valproic acid, carbamazepine in3 year were 94.3%, 81.9%, 95.4%, 96.7% and 95.9%, respectively. In all the participated laboratories, the number of fluorescence polarization immunoassay(FPIA) decreased, the number of acridinium direct chemiluminescence and enzyme-multiplied immunoassay technique(EMIT) increased every year. Approximately 92.3% of the 195 lots of EQA, the coefficient of variation of the Methods were less than 20%, 7.2% of the lots, the coefficient of variation of Methods were between 20%～30%, and 0.5% of the lots, the coefficient of variation of Methods were more than 30%. Conclusion The determination accuracy and comparability for TDM should be improved by strengthening quality control management and standardization, and it will provide the credible diagnostic reference for the clinical application.

Key words: therapeutic drug monitoring, external quality assessment