Testing COVID-19 Tests Faces Methodological Challenges

In battling the COVID-19 pandemic, testing is essential. The detection of viral RNA allows the identification of infected persons, whereas the detection of antibodies may reveal a response to a previous infection. Tests for coronavirus should be rigorously evaluated in terms of their analytical and clinical performance. This poses not only logistic challenges, but also methodological ones. Some of these are generic for the diagnostic accuracy paradigm, whereas others are more specific for tests for viruses. Problematic for evaluations of the clinical performance of tests for viral RNA is the absence of an independent reference standard. Many studies lack rigor in terms of the recruitment of study participants. Study reports are often insufficiently informative, which makes it difficult to assess the applicability of study findings. Attempts to summarize the performance of these tests in terms of a single estimate of the clinical sensitivity fail to do justice to the identifiable sources of the large heterogeneity in mechanisms for generating false negative results.