Diagnostic Laboratory Tests for COVID-19 in US: Methodology and Performance

COVID-19 is a global pandemic caused by a new coronavirus strain. Innovative tests have been developed to diagnose and characterize the spread of COVID-19. Only a few studies have reported the diagnostic value of currently available tests. The diagnostic performance of the tests is a major concern after the recent resurgence in COVID-19.

Published papers and FDA data on the currently available tests were used for analysis. Likelihood ratios, and predictive values of tests were computed. Only FDA approved tests were included. RT-PCR performance among different specimen types were also explored.

All the published reports on the COVID-19 tests reported RT-PCR as the validation tool for their results. Not all available COVID-19 tests reported their sensitivity and specificity. Among the publications which reported, the positive likelihood ratio ranged between 0.15 to 0.88 and tests had high negative likelihood ratio (0.99).

Although most recent publications showed high positive and negative likelihood ratios and high predictive values, the publications on test accuracy and validity have limited scope primarily due to their small sample size and insufficiencies in methodology and published data. Although most lab tests reported high sensitivity and specificity, false omission and false discovery rates were found notable in several COVID-19 lab tests. These results suggest need for caution on test results' interpretation. Practitioners also need to integrate evidence that is evolving rapidly.