Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 6, 2022; 10(19): 6456-6463
Published online Jul 6, 2022. doi: 10.12998/wjcc.v10.i19.6456
Field evaluation of COVID-19 rapid antigen test: Are rapid antigen tests less reliable among the elderly?
Irena Tabain, Djivo Cucevic, Nikola Skreb, Anna Mrzljak, Ivana Ferencak, Zeljka Hruskar, Anita Misic, Josipa Kuzle, Ana Marija Skoda, Hrvojka Jankovic, Tatjana Vilibic-Cavlek
Irena Tabain, Ivana Ferencak, Zeljka Hruskar, Anita Misic, Josipa Kuzle, Ana Marija Skoda, Hrvojka Jankovic, Tatjana Vilibic-Cavlek, Department of Virology, Croatian Institute of Public Health, Zagreb 10000, Croatia
Djivo Cucevic, Department of Emergency Medicine, Institute of Emergency Medicine of the City of Zagreb, Zagreb 10000, Croatia
Nikola Skreb, Anna Mrzljak, Tatjana Vilibic-Cavlek, School of Medicine, University of Zagreb, Zagreb 10000, Croatia
Anna Mrzljak, Department of Gastroenterology and Hepatology, University Clinical Hospital Zagreb, Zagreb 10000, Croatia
Author contributions: Tabain I made contributions to the conception and design of the study, and was involved in drafting and revising the manuscript; Cucevic D, Skreb N, Ferencak I, Hruskar Z, Misic A, Kuzle J, Skoda AM, and Jankovic H were involved in collecting data and drafting the manuscript; Mrzljak A and Vilibic-Cavlek T revised the manuscript critically; All authors have read and approved the final manuscript.
Institutional review board statement: The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of the Croatian Institute of Public Health (protocol code 030-02/20-05/1, approved on May 7th, 2020).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Anna Mrzljak, PhD, Adjunct Associate Professor, Department of Gastroenterology and Hepatology, University Clinical Hospital Zagreb, Kispaticeva 12, Zagreb 10000, Croatia. anna.mrzljak@gmail.com
Received: March 14, 2022
Peer-review started: March 14, 2022
First decision: March 24, 2022
Revised: April 5, 2022
Accepted: May 17, 2022
Article in press: May 17, 2022
Published online: July 6, 2022
Abstract
BACKGROUND

The global outbreak of coronavirus disease 2019 (COVID-19) leads to the development of accessible and cost-effective rapid antigen-detection tests (RATs), as quick and accurate diagnosis is crucial to curb the pandemic.

AIM

To evaluate the Humasis COVID-19 Ag Test (Humasis Co., Ltd., Gyeonggi-do, Republic of Korea) in the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).

METHODS

This retrospective study was carried out at the Croatian Institute of Public Health and included patients with clinical symptoms of COVID-19 lasting no longer than 5 d prior to testing, whose nasopharyngeal swabs were primarily tested with RAT. Negative RAT samples underwent confirmatory real-time reverse transcription-polymerase chain reaction (RT-PCR). Diagnostic efficacy was determined compared to RT-PCR. The patients were divided into three age groups (< 18, 19-65, > 65 years). Statistical analysis was performed with the significance level set at P < 0.05.

RESULTS

In total, 2490 symptomatic patients were tested; 953 samples were positive on RAT, and 1537 were negative. All negative RAT samples were subjected to RT-PCR; 266 samples were positive and marked as false-negative results on RAT. The calculated negative predictive value as a measure of RAT efficacy was 82.69%. The χ2 test and Kruskal-Wallis test showed a significant difference in the proportion of false negatives (P < 0.001) and RT-PCR cycle (Ct) values for false-negative RATs (P = 0.012) among the age groups. The young age group was significantly less likely to be false negative, whereas the false negatives from the elderly group experienced significantly lower Ct values than the other two age groups.

CONCLUSION

Evaluated RAT demonstrated satisfactory performance with more reliable results in younger patients. Humasis COVID-19 Ag RAT is potentially a valuable tool in areas where access to molecular methods is limited; however, RT-PCR remains a gold standard for SARS-CoV-2 detection.

Keywords: Coronavirus disease 2019, Severe acute respiratory syndrome coronavirus-2, Rapid antigen test, Real-time reverse transcription-polymerase chain reaction, Croatia

Core Tip: The global outbreak of coronavirus disease 2019 led to the development of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rapid antigen-detection tests (RATs), as a fast and accurate diagnosis is crucial to curb the pandemic. Evaluated RAT demonstrated satisfactory performance with more reliable results in younger patients. The young age group was significantly less likely to be false negative, whereas the false negatives from the elderly group showed significantly lower reverse transcription-polymerase chain reaction (RT-PCR) cycle values. Therefore, RT-PCR remains a gold standard for SARS-CoV-2 diagnosis.