The clinical demand for molecular tests is increasing and thus, the need for quality control is also increasing. The Korean Association of External Quality Assessment Service has operated a test proficiency program for molecular hepatitis virus testing twice a year (molecular microbiology, hepatitis virus 1, 2). The proficiency test for hepatitis virus molecular testing includes hepatitis B virus (HBV; quantitative and qualitative), hepatitis C virus (HCV; quantitative and qualitative), and HBV DNA drug resistance mutation tests. The HBV (quantitative) and HCV (quantitative) programs had the greatest number of participants, with 117 and 71 institutions, respectively, participating in the second evaluation in 2021. This represents 5.4% and 9.2% increases, respectively, compared to the first evaluation in 2016. For the remaining tests, less than 20 institutions participated, which was not sufficient to confirm an increase or decrease in the number of participants. The market share was high for the two major quantitative test manufacturers, Roche (Switzerland) and Abbott (USA), and Roche was the dominant manufacturer of the qualitative test. However, laboratory-developed tests were the main tests used to detect drug resistance mutations. The coefficients of variation for the HBV (quantitative) test for low- and high-concentration samples were 20.5% and 29.6%, respectively, while those for the HCV (quantitative) test were 37.1% and 32.3%, respectively. The percentage of intended responses for the qualitative test ranged from 85.7%–100.0% through the whole period, and was 100.0% for 2020 and 2021. The percentage of intended responses for the HBV DNA drug resistance test for three agents, adefovir, entecavir, and lamivudine, ranged from 78.6%–100.0%, 84.6%–100.0%, and 38.5%–100.0%, respectively.

Keywords: Korean Association of External Quality Assessment Service, Laboratory proficiency testing, Quality improvement, Hepatitis B virus, Hepatitis C virus, Molecular test