Northerner
Admin (Retired)
- Relationship to Diabetes
- Type 1
Maths quiz. If you take a Covid test that only gives a false positive one time in every 1,000, what’s the chance that you’ve actually got Covid? Surely it’s 99.9%, right?
No! The correct answer is: you have no idea. You don’t have enough information to make the judgment.
This is important to know when thinking about “lateral flow tests” (LFTs), the rapid Covid tests that the government has made available to everyone in England, free, up to twice a week. The idea is that in time they could be used to give people permission to go into crowded social spaces – pubs, theatres – and be more confident that they do not have, and so will not spread, the disease. They’ve been used in secondary schools for some time now.
There are concerns over LFTs. One is whether they’ll miss a large number of cases, because they’re less sensitive than the slower but more precise polymerase chain reaction (PCR) test. Those concerns are understandable, although defenders of the test say that PCR testing is too sensitive, able to detect viral material in people who had the disease weeks ago, while LFTs should, in theory, only detect people who are infectious.
www.theguardian.com
Takes a bit of thinking about, but I think I understand! 😱 🙂
No! The correct answer is: you have no idea. You don’t have enough information to make the judgment.
This is important to know when thinking about “lateral flow tests” (LFTs), the rapid Covid tests that the government has made available to everyone in England, free, up to twice a week. The idea is that in time they could be used to give people permission to go into crowded social spaces – pubs, theatres – and be more confident that they do not have, and so will not spread, the disease. They’ve been used in secondary schools for some time now.
There are concerns over LFTs. One is whether they’ll miss a large number of cases, because they’re less sensitive than the slower but more precise polymerase chain reaction (PCR) test. Those concerns are understandable, although defenders of the test say that PCR testing is too sensitive, able to detect viral material in people who had the disease weeks ago, while LFTs should, in theory, only detect people who are infectious.
The obscure maths theorem that governs the reliability of Covid testing
There’s been much debate about lateral flow tests – their accuracy depends on context and the theories of a 18th-century cleric
www.theguardian.com
Takes a bit of thinking about, but I think I understand! 😱 🙂
