The estimation of traceability and uncertainty of measurement on the result of HBV DNA with different detecting system / 中华检验医学杂志

ABSTRACT

Objective To study the uncertainty and traceability of HBV DNA assays and discuss the comparability of results among different detection systems. Methods Different detecting systems were used to detect HBV DNA using the national standard substance as "quality control substance". The uncertainty of the results was evaluated referring "Guidelines for estimating and reporting measurement uncerTAinty of chemical test results" of NATA The results were traced back to the national standard substance. According to the CLSI document EP9-A2, the results were analyzed and subjected to bias estimation with the t(0.05sv) √u2b1+ u2b2 as the criterion clinically accepted to investigate the comparability of different detecting systems. Results The means (-y) measured by 3 HBV DNA assay systems were 6.15,5.88,and 6.31 lg(kIU/L) respectively. Except system A,both the biases of system B and C had statistical significance (all P ＜ 0. 05) and expanded uncertainty of three detection systems was varied, but the difference was within the maximum acceptable range (± 0. 5) of the external quality assessment by National Center for Clinical Laboratory. Being traceable to national standard substance, the results of HBV DNA of the three detecting systems were (5.45 ± 1.23), (5.55 ± 1.32) and (5.42 ± 1.25) lg(kIU/L), respectively.There was significant difference among three systems (F = 5.63, P ＜ 0. 05). Comparing system A and B,there was significant difference in statistic (q = 5. 12, P ＜ 0. 05) and the difference between system B and C also had statistically significant (q = 6. 85, P ＜ 0. 05), but the results between system A and C had no statistical difference (q = 1.85,P ＞ 0. 05). Among these three systems, the difference of any two detection systems had no statistical significance (all P ＞ 0. 05). It showed that system bias was acceptable in clinical application and the results between different systems were comparable. Conclusions It is necessary to estimate the uncertainty and traceability when comparing the HBV DNA assay among the different labs. It also needs to estimate the bias of different systems and evaluate the clinical acceptability to ensure the accuracy and comparability of the results.