Analysis of the imprecision of internal quality control of therapeutic drug monitoring in serum(carbamazepine, digoxin, phenytoin, theophylline and valproic acid) in China, 2014 / 国际药学研究杂志

ABSTRACT

Objective To investigate the coefficient of variations(CV) of internal quality control(IQC) of therapeutic drug monitoring in serum (carbamazepine, digoxin, phenytoin, theophylline and valproic acid), and compare with the quality specification derived from allowable total error (TEa). Methods Data was collected by Web-based submission system, the 175 laboratories which enrolled in 2014 therapeutic drug monitoring in serum external quality assessment (EQA) program attended. The data included the CV of February of 2014 and long-term cumulative data, method and instrument, etc. Microsoft Excel 2013 and SPSS 13.0 was used to analyze the data.The evaluation standard of EQA was considered as TEa(25%and 20% for digoxin). 1/3TEa (8.33% and 6.67% for digoxin) and 1/4TEa (6.25% and 5% for digoxin)were determined to be the evaluation standard of CV of IQC. Results From 175 laborctories 94, 97, 61, 43 and 116 laboratories reported effective results of IQC material of carbamazepine, digoxin, phenytoin, theophylline and valproic acib, respectively. More than 60% laboratories used Bio-Rad measurement system(63.93%-76.29%). Less than 40%laboratories used other measurement systems(23.71%-36.07%). There were significant differences (P<0.05) of the acceptable rates of CV between test items (χ2 10.689-19.255, P<0.05). There was no significant difference of the acceptable rate of CV between different measurement systems except valproic acid evaluated by 1/3TEa (P<0.05). Conclusion It is an effective method for clinical laboratories to improve test quality by monitoring the current and cumulative CV of IQC and comparing them against proper evaluation criteria to evaluate if the analysis system can meet specific quality requirements or technical specification.