I think the criticism in this thread and elsewhere is a bit too harsh. It’s by no means a perfect study, nor the last word, but hopefully will motivate further studies.<p>I volunteered on this study and talked with hundreds of the participants, at least 200 and possibly as many as 400. Two reported previous COVID symptoms, unprompted.<p>The bigger problem was socioeconomic bias. Judging from number of Tesla’s, Audi’s, and Lamborghis, we also skewed affluent. Against the study instructions, several participants (driving the nicest cars I might add) registered both adults and tested two children. In general, these zip codes had a lower rate of infection. It’s very hard to understand which way this study is biased, and a recruiting strategy based on grocery stores might be more effective, but difficult to get zip code balance<p>There has been additional validation since this preprint was posted and now there’s 118 known-negative samples that have been tested. Specificity remains at 100% for these samples. An updated version will be up soon on medrxiv.