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Originally Posted by golfing eagles
Actually, I have a feeling there is a problem with this study that showed a 0.05% false positive rate. From the article:
"Researchers from the University of Toronto's Rotman School of Management published their peer-reviewed findings in the journal JAMA earlier this month. They looked at the results of more than 900,000 rapid antigen tests conducted over 537 workplaces in Canada between January and October 2021.
During this period, Canada had two significant waves of COVID-19 driven by the Delta variant. A total of 1,322 positive results were logged with rapid tests. Of these cases, 1,103 also had data from a PCR test to compare against.
In total, 462 rapid test results, or 0.05 per cent of the 900,000 results, resulted in false positives. This represents 42 per cent of the positive test results in the study."
I just find it unlikely that they only had 1,322 positive results out of 900,000 tests---that equals a positivity rate of 0.1468%, when we have been running positivity rates in the US of 20, 30, and even 40+% in some areas. Then, the "false positive" tests were 462, representing, yes, 0.05 of 900,000 but a whopping 42% of the positives. So, in other words, if your home test was positive, there is a 42% chance it is false, not 0.05%. I would think further studies are needed.
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Nice to see you read the study. I really cannot speak to the question of why the Canadian study had a low positivity rate other than to say that Canada has been extremely vigorous, or perhaps vigourous, in quarantine, masking, distancing, and convincing its citizens to take Covid seriously. The study was done in businesses on healthy persons. This did not involve people being tested because they were ill. Most of our positive Covid tests are on people with some symptoms or a defined exposure.
Secondly, as you read the study you already know how the authors explained the 42% figure, which you cite but don't explain. While the tests were done in several hundred locations, 60% of the false positives came from just 2 testing locations, from a single manufacturer and a single lot which led the authors to believe it was a faulty batch of tests. If you throw out the bad batch, which we should not when looking at data as it happens, then the rate of false positives falls to 200 out of nearly a million.
For those interested in reading the study...
HERE