Exploring the Complexity of COVID-19 Diagnostic Tests

Version 1.0

Clinical diagnoses and epidemiological surveillance of the COVID-19 pandemic relies on the availability of highly sensitive, scalable, and low-cost tests. Given the urgent and massive demand for testing in the United States, the Food and Drug Administration (FDA) has been issuing Emergency Use Authorizations (EUAs) [1] on an ongoing basis for many private test kits and laboratories. The complexity of the steps involved in testing for the presence of the SARS-CoV-2 requires each test be scrutinized from several practical dimensions. In this living document, we analyze the authorization documents published by the FDA for each test, breaking down the details of each test into the four stages of (1) sampling, (2) upstream processing, (3) amplification, and (4) readouts. We also present the reader with short descriptions of each method for every stage. Our tabulation of all the current EUA COVID-19 tests reveals authorization documents of varying rigor and quality, with many documents short on critical details on RNA extraction and purification, and also sensitivity evaluation. Many of the tests do not report sensitivity across different suggested sampling methods, even as clinicians wrestling with a choice of different sampling methods report varying sensitivity measures. We hope that this living document can serve as an exploration tool for physicians and scientists, as an educational tool for patients, and as a guide for discerning need-gaps for institutions and philanthropists. 

We published a detailed version of the COVID-19 testing technical assessment earlier [2]. Please report any errata in our tabulation here. Visualizations created by Amelia Wattenberger.

First, we break down and explore each EUA test concerning the four stages of (1) sampling, (2) upstream processing (3) amplification, and (4) readouts. For each method in a step, we denote the processing time, sensitivity, and the relative cost, along with a short description of the technique (on hover).

Next, each test is plotted as a function of its relative cost and processing time. Scalability and sensitivity of each test, which are difficult to estimate and not shown here, are two complex metrics influenced by the technique of sampling, transporting of specimen collections to centralized labs, and
other factors. 

Finally, we list all the current approved tests into a table, sortable by the test name, processing time, cost, location, and approval date.

[1] Food & Drug Administration, Emergency Use Authorizations https://www.fda.gov/medical-devices/emergency-situations-medical-devices/emergency-use-authorizations

[2] Farzadfard, F., Kang, L., Bates, S., Dinakar, K., Klein, S., Kreindler, J., … Ito, J. (2020). COVID-19 RNA Testing Technology Assessment. Interventions. https://doi.org/10.21428/9610ddb2.46de84ab