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KerriAshcroft  
#1 Posted : 21 January 2021 09:47:11(UTC)
Rank: New forum user
KerriAshcroft

Hi. I was wondering if anyone is carrying out rapid testing in their workplace? If so do you have any advice on the best kits to purchase, the actual procedure, does it have to be monitored by a health professional?

Any advice would be appreciated.

Many thanks

Kerri 

craigroberts76  
#2 Posted : 21 January 2021 11:59:04(UTC)
Rank: Forum user
craigroberts76

yes we carry it out twice a week, and it has picked up 2 people who when tested with PCR test were positive.  its a good way to help ensure the office remains safe.

We administer the tests ourselves, and as long as we follow the simple instructions its easy (exactly the same as the NHS home tests)

Roundtuit  
#3 Posted : 21 January 2021 12:24:28(UTC)
Rank: Super forum user
Roundtuit

Craig is one of the exceptions in conducting testing.

If you look at other posts on these forums many question the purpose of workplace testing and more importantly its validity and reliability.

Just like an MOT the result is "at time of test ONLY"

Roundtuit  
#4 Posted : 21 January 2021 12:24:28(UTC)
Rank: Super forum user
Roundtuit

Craig is one of the exceptions in conducting testing.

If you look at other posts on these forums many question the purpose of workplace testing and more importantly its validity and reliability.

Just like an MOT the result is "at time of test ONLY"

craigroberts76  
#5 Posted : 21 January 2021 12:38:30(UTC)
Rank: Forum user
craigroberts76

thats why we do it twice a week.  My wife works in an opticians and they are twice a week and a big chunk of the patient facing NHS (at least Cheshire E & W) are twice a week as well.

thanks 1 user thanked craigroberts76 for this useful post.
Evans38004 on 21/01/2021(UTC)
chris.packham  
#6 Posted : 21 January 2021 14:18:06(UTC)
Rank: Super forum user
chris.packham

One factor that concerns me about this type of testing is the potential for false negatives. Not only are the test systems themselves not immune to this but, more importantly, the reliability of the test depends on the quality of the samples. I wonder how many positives are missed simply because the swabs did not actually pick up the virus. One study I saw suggested that as many as 30% of all negative test results may be incorrect. Could we be in danger of a false sense of security?

craigroberts76  
#7 Posted : 21 January 2021 14:44:27(UTC)
Rank: Forum user
craigroberts76

they are 95% accurate and verified.  False negatives are the same as not testing, so if it picks up a positive then thats 100% better than not testing at all.  Its not possible to have a false positive

A Kurdziel  
#8 Posted : 21 January 2021 14:52:52(UTC)
Rank: Super forum user
A Kurdziel

The Lateral Flow Devices, which is what most people mean by rapid testing are only about 70% ie they probably miss 30% of the  positives.  They are cheap and easy to administer though. The RT-PCR tests are about 90% accurate but cost more and need more resources to carry out. There is a point care version- see  https://www.bmj.com/content/370/bmj.m3682 which can be carried be less qualified staff and does not need to go to a laboratory but it costs more to administer.

johnc  
#9 Posted : 21 January 2021 14:54:00(UTC)
Rank: Super forum user
johnc

Craig, not sure why you say that there are no false positives. I took a lateral flow test at the Council test centre and this came back as positive. I was then told to go to another test centre which sent the swab to a laboratory and this came back negative. The second test was said to be the more accurate. I have been told that this happened to another person at a different testing station.
chris.packham  
#10 Posted : 21 January 2021 16:59:43(UTC)
Rank: Super forum user
chris.packham

My concern is primarily the false positives, potentially due to inadequate sampling. So you get no positives. Does this mean your workplace is Covid-19 safe when there may be several employees who tested negative but are actually positive? In other words, and I have several peer-reviewed studies that raise this point; how reliable an indicator of the true position (and this only at the time of testing) is the workforce test?

chris.packham  
#11 Posted : 21 January 2021 17:03:16(UTC)
Rank: Super forum user
chris.packham

Apologies for typo. It should have read:  My concern is primarily with the false negatives.

Roundtuit  
#12 Posted : 21 January 2021 17:49:58(UTC)
Rank: Super forum user
Roundtuit

https://www.dailymail.co.uk/news/article-9172733/Scientists-war-Covid-lateral-flow-tests-Government-experts-blast-accuracy-critics.html

Anyone care to comment on claimed accuracy 90+% versus much lower "real world" figures.

Isn't that the current thrust of new vehicle emissions figures - the "laboratory" versus the "experience"

The only person who gave an "accurate" description of the company product was jeweller Gerald Ratner - pretty sure I will discover a moderator if I use the exact quote.

Roundtuit  
#13 Posted : 21 January 2021 17:49:58(UTC)
Rank: Super forum user
Roundtuit

https://www.dailymail.co.uk/news/article-9172733/Scientists-war-Covid-lateral-flow-tests-Government-experts-blast-accuracy-critics.html

Anyone care to comment on claimed accuracy 90+% versus much lower "real world" figures.

Isn't that the current thrust of new vehicle emissions figures - the "laboratory" versus the "experience"

The only person who gave an "accurate" description of the company product was jeweller Gerald Ratner - pretty sure I will discover a moderator if I use the exact quote.

achrn  
#14 Posted : 22 January 2021 10:04:54(UTC)
Rank: Super forum user
achrn

Originally Posted by: craigroberts76 Go to Quoted Post

they are 95% accurate and verified.  False negatives are the same as not testing, so if it picks up a positive then thats 100% better than not testing at all.  Its not possible to have a false positive

Some rather more expert people disagree with you: https://www.bmj.com/content/371/bmj.m4941

"Jon Deeks, professor of biostatistics at Birmingham and leader of the Cochrane Collaboration’s covid-19 test evaluation activities, explained the results. ... We thus estimate that we found 2 cases and will have missed 60"

and

"Scottish universities and colleges tested students from 30 November to  13 December, conducting a total of 43 925 lateral flow tests across all  test sites. Of these, 79 (0.2%) were positive, although preliminary analysis of 31 of these positive samples showed that only 13 were positive on PCR testing, giving a false positive rate of 58%."

chris.packham  
#15 Posted : 22 January 2021 10:14:27(UTC)
Rank: Super forum user
chris.packham

'RT-PCR tests are highly sensitive, but can show false negatives (giving a negative result for a person infected with Covid-19) and false positives (giving a positive result for a person not infected with Covid-19)'

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/895843/S0519_Impact_of_false_positives_and_negatives.pdf

craigroberts76  
#16 Posted : 22 January 2021 18:08:14(UTC)
Rank: Forum user
craigroberts76

The tests pick up the protein strand, if you have it, cross contaminate it or somehow do the test wrong then you could be detected as positive when you're not.. however unless the protein is present that triggers the test, then it cannot say its positive.  

https://www.gov.uk/government/publications/sars-cov-2-lateral-flow-antigen-tests-evaluation-of-vui-20201201/sars-cov-2-lateral-flow-antigen-tests-evaluation-of-vui-20201201?mc_cid=e934dc94f3&mc_eid=cd3885d461 

But even so, no testing is never going to detect any infection

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