The SENSITIVITY of the PCR-test is the number of people with COVID the test claims to accurately identify. The claimed sensitivity varies from about 70% to 90%, depending on the source. 70% sensitivity means that 7 out of 10 people who have COVID will be identified as 'positive' by the test.
The SPECIFICITY of the test is the percentage of people who DON'T have COVID who are accurately identified. The claimed specificity varies from about 95% to 99% accuracy. The very significant point to recognise here is that between one and five percent of testees who don't have the virus will test positive for COVID.
Taking a period in the UK (May 11-24th ) when the official estimated percentage of people with COVID was 0.24%, let us see how these figures play out if (this number doesn't affect % outcomes) 100,000 people were tested at that time.
0.24% of 100,000 people is 240 so at this time 240 people (of the 100,000) actually had COVID-19
Taking the highest quoted accuracies (SENSITIVITY 90%, SPECIFICITY 99%)
We see that 0.9 x 240 = 216 would test positive, 24 would be missed (negative result).
Of the 99,760 who do not have COVID, 1% will test positive. That is about 997 people.
So that total number of positive tests is 216 + 997 = 1213 people identified as having COVID
1213/240 = 5.05 ...
THE NUMBER OF POSITIVE TEST RESULTS IS 5 TIMES THE NUMBER THAT "HAVE" THE VIRUS.
So, if you take the test and are identified as COVID positive there is, USING THEIR OWN BEST ESTIMATE, only a one-in-five chance that you are really 'infected' (AS YOU WILL HAVE JUST BEEN INFORMED).
Worth knowing, don't you think? Just as well there are all those "asymptomatic" COVID carriers out there to make sense of this pantomime. It is hard not to laugh. Are you starting to get an idea of the absolute bullsh*t we are dealing with here?
Taking the lowest quoted accuracies (SENSITIVITY 70%, SPECIFICITY 95%)
There are still 240 people with COVID.
0.7 x 240 = 168 would test positive, 72 missed (negative result)
5% of negatives test positive, i.e. 0,05 x 99760 = 4988 positives
so, the total number of positive tests is 168 + 4988 = 5156 people identified as having COVID. 5156/240 = 21.5 !!!
THE NUMBER OF POSITIVE TEST RESULTS IS MORE THAN 20 TIMES THE NUMBER THAT "HAVE" THE VIRUS.
Therefore, if "accuracy" is the minimum quoted, for a person who is told they have tested positive for COVID there is less than one chance in twenty that you are infected with the virus you have JUST BEEN INFORMED is in your body.
Whatever COVID actually is (there is zero proof for causation by virus) it is, given the above, fair to say that there is poor correlation between PCR test results and this world-altering pandemic/illness.
Assuming that any chest-infection-type-illness can currently be considered to be part of the COVID basket we might ask ourselves what kind of "test results" might we get if we used some other indicator of the illness rather than the PCR test, which fails so badly to do its job?
What if people were not told what the test was, just that they'd had it and here is your COVID-positive or COVID- negative result? What if the secret test had been adjudged to be POSITIVE if a person was:
a) Wearing a red jumper?
Well, the percentage of the total would be appropriately small. It might work on that level. It could turn out that the number of people with chest infections and the number wearing red jumpers are very similar. However, it is very unlikely they will be the same people, which is a shame given that it would produce excellent local cause for lock-down in areas close to certain schools with a red uniform. However. Sadly.
This COVID test would certainly FAIL.
b) Wearing a white shirt/top?
A much better idea. A much larger sample to work with and, given that most COVID hosts are asymptomatic, many more people in the community with chest infections will fall into the correct basket. If more than one in twenty white-toppers have chest infections this could be a winner and what is more (Golly Gee!) EVERYONE in hospital with a chest-infection will 'test' positive. They're all white-topped in there.
This COVID test could be a WINNER!
c) Carrying or within arm's length of paper tissues?
Anyone who is found to be either carrying tissues in their pocket or in a bed with tissues at hand. The State could do stop-and-search testing. Show us what's in your pockets and we'll tell you if you've got COVID. This one would work perfectly because even if a positive testee is perfectly healthy they probably think they are ill. It works on every level ... in your house, on the street, in hospital. Outcomes will be fantastically accurate. Those who test positive will believe it every time. Those who test negative will know there's nothing wrong with them. The correlation will be almost perfect. Deaths ? Well, I mean ... what kind of Flu victim walks around with a wheezy chest, a runny nose and NO TISSUES IN THEIR POCKET? Someone must tell Boris Johnson straight away.
This COVID test is THE VERY BEST.
If ABSOLUTE NONSENSE can model an illness better than SCIENCE perhaps the public will begin to realise that this SO-CALLED-SCIENCE is ABSOLUTE NONSENSE.