geoffrey modest medical blogs

  a recent large Canadian study confirmed that there were very few false positive results in rapid antigen tests for SARS-CoV-2 virus, and that the limited number of false positives were largely from manufacturing issues of the tests (see  covid false pos rapid antigen rare JAMA2022 in dropbox, or doi:10.1001/jama.2021.24355)   Details: -- Canada implemented their Creative Destruction Lab Rapid Screening Consortium (CDL RSC) in order to help protect against Covid transmission in workplaces     -- this program was set up to inform the operational requirements of rapid antigen screening in workplaces -- asymptomatic employees were screened twice weekly, on a voluntary basis -- data collected from January 11 to October 13, 2021 during which there were two significant Delta variant waves (March to June and August to October) -- screening results were recorded, including the place of employment, the test done, and (optionally) the lot number of the...

  A recent NIH study  (Testing Us At Home study) found that rapid antigen testing was as accurate for  the omicron as the delta variants, in a pre-print, pre-peer reviewed article (see   covid rapid antigen test accurate medrvix202 2 in dropbox, or  https://www.medrxiv.org/content/10.1101/2022.02.27.22271090v2.full.pdf  or  doi.org/10.1101/2022.02.27.22271090  ). Of note, this was NOT a pre-specified study analysis, but developed to answer another question (not being a pre-specified analysis might diminish the statistical rigor associated with a new study) Details: -- 5,506 participants without symptoms were enrolled from 18October2021 to 24January2022, and received rapid antigen (Ag-RDT) and nasal  PCR tests every 48 hours for 15 days, all nasal tests self-administered (with a 15-minute break between samplings)     --Ag-RDT tests used (all approved EUA tests):          -- BD Veritor At-Home, Quidel Qui...