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BBC News - Coronavirus antibodies tests 'put public at risk' https://www.bbc.co.uk/news/health-53853967
Our review of websales of COVID-19 antibody tests reported after @BBCNewsnight with @deb_cohen @charliehtweets last night. Joint work Uni Birmingham @UoB_IAHR @TERG_UoB and Uni Warwick.
1/11
Our review of websales of COVID-19 antibody tests reported after @BBCNewsnight with @deb_cohen @charliehtweets last night. Joint work Uni Birmingham @UoB_IAHR @TERG_UoB and Uni Warwick.
1/11
Full report is available as a pre-print led by @siantphillips2
Information given by websites selling home self-sampling COVID-19 tests: An analysis of accuracy and completeness https://www.medrxiv.org/content/10.1101/2020.08.18.20177360v1
2/11
Information given by websites selling home self-sampling COVID-19 tests: An analysis of accuracy and completeness https://www.medrxiv.org/content/10.1101/2020.08.18.20177360v1
2/11
A simple search of UK and US websites (end of May) found 27 websites selling 41 tests direct to user home self-sampling and testing for COVID-19. Seems a particular UK problem as 39 tests were for sale in UK and only 2 in US.
3/11
3/11
Many websites DID NOT provide
the name or manufacturer of the test (32/41; 78%),
when to use the test (10/41; 24%),
test accuracy (12/41; 29%),
how to interpret results (21/41; 51%).
4/11
the name or manufacturer of the test (32/41; 78%),
when to use the test (10/41; 24%),
test accuracy (12/41; 29%),
how to interpret results (21/41; 51%).
4/11
Sensitivity and specificity were the most commonly reported test accuracy measures
either were reported for 27/41 (66%) tests;
We tried to link these to evidence - but could only link these figures to manufacturers documents or publications for four (10%) tests.
5/11
either were reported for 27/41 (66%) tests;
We tried to link these to evidence - but could only link these figures to manufacturers documents or publications for four (10%) tests.
5/11
Predictive values were not reported but indirectly implied
for 5 tests wesbites said “if it shows a positive result, it can only be for COVID-19” implying PPV=100%
four tests stated that tests sometimes show a negative result even if you are infected implying NPV<100%
6/11
for 5 tests wesbites said “if it shows a positive result, it can only be for COVID-19” implying PPV=100%
four tests stated that tests sometimes show a negative result even if you are infected implying NPV<100%
6/11
For molecular virus tests,
only 9/23 (39%) websites explained that test positives should self-isolate,
and 8/23 (35%) explained that test negatives may still have the disease.
7/11
only 9/23 (39%) websites explained that test positives should self-isolate,
and 8/23 (35%) explained that test negatives may still have the disease.
7/11
For antibody tests,
12/18 (67%) websites explained that testing positive does not necessarily infer immunity from future infection.
8/11
12/18 (67%) websites explained that testing positive does not necessarily infer immunity from future infection.
8/11
Seven (39%) websites selling antibody tests claimed the test had a CE mark, when they were for a different intended use (venous blood rather than finger-prick samples).
9/11
9/11
After MHRA stopped use of finger-prick samples
2 websites still selling
4 providing venous blood sampling
2 sent kits for purchaser to find own phlebotomist
6 stated out of stock / unavailable,
4 reported MHRA guidance and indicated that they had suspended sales.
10/11
2 websites still selling
4 providing venous blood sampling
2 sent kits for purchaser to find own phlebotomist
6 stated out of stock / unavailable,
4 reported MHRA guidance and indicated that they had suspended sales.
10/11
Conclusions:
Web sales of home self-sampling COVID-19 tests
provide incomplete and in some cases misleading information about:
test accuracy,
intended use
and
test interpretation.
We MUST DO BETTER. Can the regulators read our paper and help?
@MHRAgovuk
11/11
Web sales of home self-sampling COVID-19 tests
provide incomplete and in some cases misleading information about:
test accuracy,
intended use
and
test interpretation.
We MUST DO BETTER. Can the regulators read our paper and help?
@MHRAgovuk
11/11
