2022 Volume 71 Issue 4 Pages 624-632
The coronavirus disease 2019 pandemic has led to the widespread use of molecular diagnostics in many clinical laboratories in Nara Prefecture. Since the results of molecular diagnosis have a significant impact on society as a whole, high accuracy and precision are required. Therefore, the Nara Association of Medical Technologists conducted an external quality assessment (EQA) of the molecular diagnosis of SARS-CoV-2 RNA in July 2021. The EQA samples consisted of three SARS-CoV-2-positive samples and one SARS-CoV-2-negative sample. Two samples with high (sample 1) and low (sample 3) Ct values prepared from patient specimens and commercial SARS-CoV-2-positive control (sample 4) were used as SARS-CoV-2-positive samples, and nuclease-free water (sample 2) was used as a SARS-CoV-2-negative sample. The evaluation was conducted on the basis of qualitative results, and for some reagents, we asked the manufacturer to measure EQA samples and evaluated the results as reference data. Forty tests with 12 different reagents from 26 laboratories were included in this EQA. The correct answers for each sample were as follows: “Sample 1” 62.5% (25/40); “Sample 2” 100% (40/40); “Sample 3” 95.0% (38/40); and “Sample 4” 67.5% (27/40). Since the incorrect results for some reagents were consistent with the manufacturer’s reference data, the detection sensitivity of the reagents and their compatibility with the samples were considered to be the factors. The results of the participating facilities reflected the characteristics of the samples and reagents, indicating the validity of this project. We believe that this EQA will contribute to the continuous maintenance and management of the quality of molecular diagnostics at the participating facilities.
