Statistics, Department of



Discussion on “Is group testing ready for prime-time in disease identification”


Christopher R. Bilder

Joshua M. Tebbs

Christopher S. McMahan

Date of this Version



Statistics in Medicine. 2021;40:3881–3886.

DOI: 10.1002/sim.8988


© 2021 John Wiley & Sons, Ltd

Link to free copy at PubMed Central


Is group testing ready for prime-time in disease identification? Yes! Prior to the COVID-19 pandemic, group testing (also known as pooled testing and specimen pooling) was widely used in areas including blood donation screening,1,2 infectious disease testing in animals,3,4 sexually transmitted infection testing,5,6 and surveillance for pathogen contamination of food.7,8 More areas could definitely benefit as well, as pointed out by Haber et al9 (HMA). The use of group testing for SARS-CoV-2 detection was isolated at the beginning of the pandemic, but early accounts of its successful implementation10-12 with little if any loss of accuracy led to its widespread use. More than 100 papers detail its implementation since April 2020. A large number of news media accounts, such as in the Washington Post,13 ABC News,14 and National Public Radio,15 likely led to its adoption as well. Large laboratories, like LabCorp16 and Quest Diagnostics,17 received Emergency Use Authorizations (EUAs) from the Food and Drug Administration to use their assays with group testing. There is even a Wikipedia18 web page dedicated to the use of group testing during the pandemic. Therefore, not only is group testing ready for “prime-time”, but it is an established “hit” among laboratories around the world to increase testing capacity. The focus of HMA is on the accuracy of group testing, in particular the first-stage sensitivity for Dorfman testing. We completely agree that quantifying this accuracy is extremely important for laboratories. Where we differ from HMA is how to account for the first-stage sensitivity. In our discussion, we provide comments on the methods used by HMA. Next, we discuss how laboratories choose a group size to insure first-stage sensitivity is not compromised. Relative to this discussion, we provide information about how to find the optimal group size. We conclude with reasons beyond accuracy for why some laboratories may remain hesitant toward group testing. We also conclude with what is next for laboratory implementation of group testing. Because of the worldwide importance of SARS-CoV-2 detection right now, our discussion focuses mostly on this group testing application.