# Incorrect Results given for Tests



## llgon (13 Apr 2020)

Paul Reid, at the HSE briefing, acknowledges that some people have been given negative results, only to be phoned later to be told they were positive.  It is something they are looking into at the moment and he doesn't know numbers involved. It seems to have occurred in recent days.


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## llgon (13 Apr 2020)

HSE: 'Less than 100 people' informed by text with mistaken Covid-19 status
					

The HSE could not provide a figure for how many people had received the incorrect messages.




					amp.irishexaminer.com


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## mathepac (13 Apr 2020)

No mention on the Government's primary PR outlet's 6 o'clock broadcast, unsurprising now.


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## Leper (13 Apr 2020)

I don't know how anybody can be surprised at this.


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## Bigbangr1 (13 Apr 2020)

Unreal


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## Brendan Burgess (14 Apr 2020)

mathepac said:


> No mention on the Government's primary PR outlet's 6 o'clock broadcast, unsurprising now.



Extensively covered on the 9 pm news last night.

Extensively covered on Morning Ireland just now.

100 people were given the wrong result out of thousands who were tested? 

And don't forget the main purpose of this test is not for the health of the individual, it is for the health of the population. 

It is not like a false negative on an early cancer test, where the treatment would be different. 

Brendan


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## llgon (14 Apr 2020)

Brendan Burgess said:


> It is not like a false negative on an early cancer test, where the treatment would be different.



Nevertheless it can still result in harm. An individual awaiting a test result should be in self-isolation (for first 14 days after symptoms anyhow). If they are given a false negative result they can end this and potentially infect those they come in contact with. 

Many of those being tested now are healthcare workers who are being prioritised for testing to speed up their return to work.  We don't have enough detail about this yet.


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## Brendan Burgess (14 Apr 2020)

llgon said:


> Nevertheless it can still result in harm.



Which is what I said, if indirectly.



Brendan Burgess said:


> it is for the health of the population.



My main point is that these people who got the wrong test results are not victims, it's the people who they come into contact with who  might be.

But 100 people with Covid, who think that they don't have it, is not big in the general scheme of things. 

If I had been told 3 weeks ago that I did not have Covid, I should still self isolate as I might have become infected since the test was done.


Brendan


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## mathepac (14 Apr 2020)

Brendan Burgess said:


> 100 people were given the wrong result out of thousands who were tested?


And those 100 people had how many contacts each that have to be traced retrospectively creating additional work? And besides, the government is lagging behind their own swabbing and testing targets, and members of at the risk might have been infected or denied timely treatment.


Brendan Burgess said:


> And don't forget the main purpose of this test is not for the health of the individual, it is for the health of the population.


I don't agree. Constitutionally we treat individuals, all of them, equally; the notion of treating citizens as herds is, I believe,  a British Conservative notion.


Brendan Burgess said:


> It is not like a false negative on an early cancer test, where the treatment would be different.


A bit puzzled here Brendan. I thought the idea of testing was to identify those in need of treatment and isolation in the event of a positive test, and continued self-isolation and social distancing if testing proved negative.


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## EmmDee (14 Apr 2020)

mathepac said:


> A bit puzzled here Brendan. I thought the idea of testing was to identify those in need of treatment and isolation in the event of a positive test, and continued self-isolation and social distancing if testing proved negative.



Not really. The testing is primarily to provide data in aggregate to feed into modeils to anticipate health system demand and manage resources.

The current testing is of limited use for individual management. The testing only informs whether you have the active virus at the moment of the testing. It says nothing about an hour later. So on a micro level, the testing is of limited use. At macro level it informs trends which is why the "sampling" approach is acceptable as opposed to testing everyone. It is also why people should act as if they have it anyway. And unless symptoms are bad, the best treatment is to manage it at home.

Antibody testing is what is needed for individual management - knowing whether you have had the virus or not, is what allows individual treatment.


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## llgon (14 Apr 2020)

Brendan Burgess said:


> If I had been told 3 weeks ago that I did not have Covid, I should still self isolate as I might have become infected since the test was done.



This is extreme and not what the HSE advise.  

Healthcare and essential workers would be returning to work.


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## Leo (14 Apr 2020)

mathepac said:


> And those 100 people had how many contacts each that have to be traced retrospectively creating additional work?



That all depends on a number of factors, but most particularly on how many of them ignored the advice they were given around isolation and distancing. There's a considerable false-negative element to these tests, so all those being tested were being told to isolate as if they had it.


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## Brendan Burgess (14 Apr 2020)

Leo said:


> There's a considerable false-negative element to these tests



That is a very good point. 

Does it matter if the test shows you are negative, but it's a false negative, and you actually have the virus 

Or 
The test showed you were positive, but due to a communications error, you were told you were negative? 

@Leo,  do you know what the false negative rate is? 

Brendan


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## Leo (14 Apr 2020)

Brendan Burgess said:


> @Leo, do you know what the false negative rate is?



It varies from test to test, and from tester to tester, but I've seen reports from studies showing false negative rates up to 40%, example. 

Some suggestions are that those drafted in to carry out the swaps aren't being thorough enough (going deep for nasal swabs for example), but in the hospital where my wife works they have had multiple patients in critical care with scans clearly showing the tell-tale patterns where tests performed in the unit have come back clear only for a second or third test to come back positive in the following days.


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## llgon (14 Apr 2020)

Leo said:


> There's a considerable false-negative element to these tests, so all those being tested were being told to isolate as if they had it.



This is not correct Leo. In some cases healthcare workers can return to work two days after symptoms *if* they have tested negative. 

If they were not tested/result unknown or tested positive, five days is the minimum, both for self-isolation and return for work.

The minimum 14 day period since first symptoms can also be shortened dependent on circumstances.

Para 10.6:

[broken link removed]


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## Leo (14 Apr 2020)

llgon said:


> This is not correct Leo. In some cases healthcare workers can return to work two days after symptoms *if* they have tested negative.



Health care workers are a special case, we're talking the general population here.


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## 24601 (14 Apr 2020)

The reaction to this has been a bit over the top from some. The Twitter thread here provides a good breakdown of the issues. 


__ https://twitter.com/i/web/status/1249834232115007495


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## mathepac (14 Apr 2020)

There is a difference between false negatives and indeterminate results and test results that were communicated incorrectly but later corrected. Please don't confuse the issues.


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## Leper (15 Apr 2020)

OK! some results come back from Germany presumably something like as follows:-
Name and Reference
Positive Yes or No

How did the person reading the results get confused with the words "Yes" or "No"? 
And if I ever qualify to participate  in 'The Chase' who was  this person in case he/she is on the same team? (On which I'll advise him/her to take the 'Low' offer.


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## Leo (15 Apr 2020)

Leper said:


> How did the person reading the results get confused with the words "Yes" or "No"?



The problem is there are more options than yes and no, but the people who put the IT system (likely just an ETL job, but I've no insight) in place to convey results from the lab test results database to the one used by those doing the communications and contact tracing weren't aware of this. So that system was incorrectly setting the results of inconclusive tests to negative when passing them to the other system. 

It's not clear when, but an internal review picked up on the anomaly but they were able to re-test many samples that provided the inconclusive results and less than a hundred of those came back positive.

It's not really that surprising that something put together in such a hurry had issues.


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## Brendan Burgess (15 Apr 2020)

Leo said:


> It's not really that surprising that something put together in such a hurry had issues.



Excellent point.


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## Ciara8x (15 Apr 2020)

llgon said:


> This is extreme and not what the HSE advise.
> 
> Healthcare and essential workers would be returning to work.



Hi, I'm a healthcare worker in an acute hospital....if we have close contact with an infected patient without PPE then we self isolate for 14 days regardless of our test result. If we have new onset symptoms then we self isolate for 5 days after symptoms have stopped, even if our test comes back negative. The possibility of false negatives is taken quite seriously in the hospital settings.


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## llgon (15 Apr 2020)

Yes Ciara, I'd expect all hospitals are following the HPSC guidelines I referenced earlier in the thread.


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