Lateral Flows
If it’s +ve you have Covid
If it’s -ve you might still have Covid as it’s got a high false negative rate & for many it may not turn +ve until days into an infection
So why test?
Because a positive confirms a Covid infection
A negative is less useful obviously 🧵
If it’s +ve you have Covid
If it’s -ve you might still have Covid as it’s got a high false negative rate & for many it may not turn +ve until days into an infection
So why test?
Because a positive confirms a Covid infection
A negative is less useful obviously 🧵
This is described as low test sensitivity (so it may not always turn positive straight away when infected), but a reasonable test specificity (you don’t get many false positives, ie if it’s positive then it’s Covid).
If you did 3 tests and got 1 +ve and 2 -ve you have Covid
If you did 3 tests and got 1 +ve and 2 -ve you have Covid
Due to the false negative risk, it’s recommended to retest on serial days after exposure or if you have symptoms especially.
They are useful tools, but imprecise & due to false negatives can be falsely reassuring if you aren’t aware of this.
They are useful tools, but imprecise & due to false negatives can be falsely reassuring if you aren’t aware of this.
Also; if it says check after 10 mins or 15 mins or what ever the instructions are, follow them.
That means don’t do it & immediately look at it & bin it before it’s had time to actually analyse.
That means don’t do it & immediately look at it & bin it before it’s had time to actually analyse.
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