Rapid Covid test - current rate of false negatives?

[SKL]

I scheduled my quarantined kid for a rapid test tomorrow.  I was wondering, if the test is negative, what are the chances it's a false negative?  (What %?)  I was thinking to get both the rapid test and the mail-away one, but the "free" locations only offer one or the other, and I am impatient for some kind of answer.

[mommyoffive]

Good question.  I have lost track of what the answer is on this, so I am interested to see what everyone says.

[Catwoman]

12 minutes ago, SKL said:

I scheduled my quarantined kid for a rapid test tomorrow.  I was wondering, if the test is negative, what are the chances it's a false negative?  (What %?)  I was thinking to get both the rapid test and the mail-away one, but the "free" locations only offer one or the other, and I am impatient for some kind of answer.

Are you sure none of the locations in your area are doing both tests at once? That’s how they do it here. 

It might be worth calling around and asking. 

 

Edited to add — I’m not sure ALL of the locations near me are doing both tests, but the people I know who have been tested said that was how they did it at the testing centers they visited. 

Edited April 23, 2021 by Catwoman
Clarification

[SKL]

3 minutes ago, Catwoman said:

Are you sure none of the locations in your area are doing both tests at once? That’s how they do it here. 

It might be worth calling around and asking. 

 

Edited to add — I’m not sure ALL of the locations near me are doing both tests, but the people I know who have been tested said that was how they did it at the testing centers they visited. 

Well, to be more specific, there are few doing the "rapid test," and the one in my area that is doing the "rapid test" is not doing the other one.  Or if they are, it does not show up on the web.

I figure I can ask about the slow test when I go there tomorrow.  If they have it, great.  If we get a positive, I'm assuming it's accurate.  If we get a negative, I can move to the next step.

[Catwoman]

1 minute ago, SKL said:

Well, to be more specific, there are few doing the "rapid test," and the one in my area that is doing the "rapid test" is not doing the other one.  Or if they are, it does not show up on the web.

I figure I can ask about the slow test when I go there tomorrow.  If they have it, great.  If we get a positive, I'm assuming it's accurate.  If we get a negative, I can move to the next step.

That sounds like a good plan! 

Hopefully, your dd’s test will be both negative AND accurate!

[Swimmer1112]

https://www.hearthsidemedicine.com/post/rapid-covid-tests-we-have-them-but-how-accurate

It looks like the false negative could be up to 50%

[Penelope]

I thought that if you get a positive, you need a confirmatory PCR. 
 

Negative is meant to be accurate enough for determining whether you are infectious or not at the time you take it. It will miss some cases of infection, but the false negative rate is comparable to PCR. The risk of missing one with a high enough viral load that would make you infectious is low. Rapid antigen is supposed to be a much better test for figuring out if you need to isolate or not.

 

[JumpyTheFrog]

If you can find out the exact name of the rapid test, you can then look up its sensitivity rate. That number will tell you what percent of true positives the test will show as positive. For example, if the sensitivity rate is 85% then it means 15% of actual cases will return a negative result.

[ktgrok]

11 minutes ago, Penelope said:

I thought that if you get a positive, you need a confirmatory PCR. 
 

Negative is meant to be accurate enough for determining whether you are infectious or not at the time you take it. It will miss some cases of infection, but the false negative rate is comparable to PCR. The risk of missing one with a high enough viral load that would make you infectious is low. Rapid antigen is supposed to be a much better test for figuring out if you need to isolate or not.

 

But it only means you don't have a high viral load that minute. Which makes it decent for people testing frequently, but not as a one and done, since you could be contagious the next day. 

A PCR will tell you , hopefully, if you are infected at all. 

[Penelope]

24 minutes ago, ktgrok said:

But it only means you don't have a high viral load that minute. Which makes it decent for people testing frequently, but not as a one and done, since you could be contagious the next day. 

A PCR will tell you , hopefully, if you are infected at all. 

Maybe PCR is better if it is a one and done when you know the date of exposure.

But rapid antigen is considered an equal option by the CDC for ending quarantine at 7 days with a negative test on day 5 or later. 
And it is definitely being used that way, as a one and done.

[ktgrok]

3 minutes ago, Penelope said:

Maybe PCR is better if it is a one and done when you know the date of exposure.

But rapid antigen is considered an equal option by the CDC for ending quarantine at 7 days with a negative test on day 5 or later. 
And it is definitely being used that way, as a one and done.

Right, but it isn't more accurate.