Comparative accuracy of COVID-19 qualitative rapid tests and quantitative molecular assays

Introduction: Coronavirus Disease 2019 (COVID-19) is transmitted at an exceptionally high rate with a much higher mortality rate than the seasonal influenza It is difficult for the mildly symptomatic or asymptomatic patients to know when to quarantine as the evidence suggest that patients are most contagious before symptoms Testing is at the forefront of combating COVID-19 but it is difficult to find a fast and reliable test that does not require sophisticated laboratories Research Question or Hypothesis: How accurate are the current COVID-19 qualitative rapid tests in detecting the virus compared to the quantitative molecular assays? Study Design: Literature Review Methods: This literature review compares eight different rapid (minutes/hours) real time reverse transcription-polymerase chain reaction (RT-PCR) or antigen tests with laboratory-controlled RTPCR quantitative assays (days) to determine positive predictive agreement (PPA) and negative predictive agreement (NPA) through studies found on PubMed using keywords The laboratorycontrolled RT-PCR tests were used as a reference because of their quantitative accurate approach The RT-PCR-based Abbott ID NOW® was the most featured rapid test because it is used at several rapid testing sites Results: Over 1300 tests conducted with the Abbott ID NOW® showed 78 7% PPA and almost 100% NPA with an average test time of 13 minutes The Cepheid Xpert Xpress®, another RT-PCR-based rapid qualitative test, had a much higher PPA of 98% but had only 96% NPA with 45-minute test time Among the antigen tests, the immunofluorescence-based Bioeasy test had the most accuracy with 93 9% PPA and 100% NPA but the median cycle threshold was 17 1 Conclusion: With the most commonly used rapid test having <80% PPA, there is room for improvement in COVID-19 point-of-care testing;however, other rapid tests have the drawbacks of longer wait time or inability to detect low viral load Thus, patients receiving a negative result on a rapid COVID-19 test, may follow-up with a quantitative test to confirm