MedCram - Medical Lectures Explained CLEARLY
2 HN recommenders · recommended in 3 months, 2020–2021
17:06 · 205K views · Jul 20, 2020
MedCram's Dr. Roger Seheult summarizes a discussion with Dr. Michael Mina on cheap, paper-based at-home COVID-19 antigen tests. It explains why lower sensitivity can still work well for screening infectious people.
Pointed to in 2020 testing threads for a visual explanation of why rapid antigen tests still serve a purpose.
3 comments from Hacker News
> But if the rapid tests are as unreliable in general as they were for me, it’s sort of no wonder COVID is spreading like wildfire. Many rapid tests are indeed not accurate[1] but they still serve a purpose, depending on the sensitivity and specificity of the tests[2]. For the rapid tests with high sensitivity and you get a positive result, it's highly likely you have COVID. For the rapid tests with high specificity and you get a negative result, it's highly likely that you don't have COVID. And the public health measures of testing / contact tracing ONLY works if testing results come back quick. PCR tests are neither fast nor cheap, so those are not as effective in prevention of spreading because you don't do those all the time (slow + expensive). Medcram has a good video talking about this. [3] [1]: [LINK] [2]: [LINK] [3]: this video
Right - see the MedCram lectures on the topic: How to Beat COVID-19 with At-Home, Rapid Result Testing: 5 Min. Summary by Dr. Mina (Antigen Tests) [LINK] Coronavirus Pandemic Update 98: At Home COVID-19 Testing - A Possible Breakthrough (~ 15 min) this video At Home, Cheap, COVID-19 Tests with Results in 15 Minutes: How to Fix Testing with Dr. Michael Mina (~ 1 hr) [LINK]
The visual explanation of the ideas and concepts presented there, also mentioned in the later podcast: Medcram: “Coronavirus Pandemic Update 98: At Home COVID-19 Testing - A Possible Breakthrough” this video Also, regarding the Ct value, from: “Interpreting the COVID-19 Test Results: a Guide for Physiatrists” [LINK] In PCR tests “the diagnosis is made based on the threshold cycle (Ct) value. Ct is defined as the cycle number when the sample fluorescence exceeds a chosen threshold above the calculated background fluorescence.5 In other words, the lower the Ct value of a specific gene, the more the gene exists in the sample. However, the problem with a Ct-based diagnosis is that there is no absolute or constant Ct cut-off value, and Ct cut-off values are different for each diagnostic reagent even for the same gene.”