The UK urgently needs an independent Covid Mass Testing Committee to ensure we do not continue to waste money and mislead citizens, argues Margaret McCartney
Colleges and universities are testing students for covid-19 before they leave campus and return home for Christmas. Directed by the UK government, universities have been issued with guidance on using lateral flow tests. Students are tested twice, three days apart, and if they test negative, they are then allowed to return home. If they test positive, they have to self isolate at university for 10 days, along with members of their households and contacts.
After the sharp rise in covid-19 cases in universities at the start of term, many students—who have been enormously restricted during term—must be aching to get home. The test is voluntary and there are concerns that many will refuse to take the test so that they can return home. Not all universities are taking part in this programme either.
This mass testing plan is, in my view, a screening programme—testing asymptomatic students who feel well. I’ve been writing about screening for over two decades, and it’s clear that: 1) politicians like screening and generally want more; 2) they don’t understand its limitations and harms; 3) we require independent scrutiny to stop ineffective screening; 4) it is crucial that people have accurate information in order to ethically consent to screening.
I would like to report that these issues have improved. I would like to say that learning has resulted in structural changes that endure past short term memory and stop us needlessly repeating mistakes. But, if the covid-19 pandemic is a test, so far, we have failed badly.
Firstly, on accuracy. The government guidance to universities states that lateral flow tests have “high specificity, but slightly lower sensitivity… Two consecutive tests 3 days apart increase the total sensitivity of LFD tests to almost the same level as RNA PCR tests.” This would depend on what one means by “slightly.” A report from the Joint Public Health England Porton Down and University of Oxford found high specificity (with a false positive rate of 0.39%).  But it is important when prevalence is low, as false positives can outweigh true positives, leading to unnecessary isolation. Nor is this a test for infectiousness. NHS advice to staff is not to do lateral flow test for 90 days after a positive PCR.  An effective screening test would reduce the burden of harm, but given that fewer than 20% of people isolate following a positive test, testing may find cases, but be ineffective in stopping spread. 
For “self trained members of the public given a protocol” the false negative rate is 42.5%. However, this validation used PCR testing as the gold standard, which itself has a false negative rate of up to 29%.  The claim that two negative lateral flow tests are as good as one negative PCR is, as far as I can see, unsubstantiated. Taking the test twice does not necessarily reduce the risk of a false negative as difficulty taking the sample correctly may occur sequentially. The test kit clearly states that it is recommended for symptomatic people only, not asymptomatic people.  The government has spent a staggering 496 million pounds on these Innova lateral flow tests.  It is a scandal that a test with such a high failure rate, not recommended for asymptomatic testing, is in mass use outside a trial setting.
A negative test may give students false reassurance and lead to more risky behaviour that would have occurred without the test. The government has told universities the exercise is designed “To enable students to make informed decisions regarding their return home for Christmas, minimising the risk of spreading the virus to vulnerable people at their destination”. But the messaging from multiple universities, who are each making their own version of information, resulting in needless effort and variability, does not necessarily explain the risk and meaning of a false negative.
So, for example, Manchester University says: “this is a really important part of helping to reduce transmission—it will help keep you, your fellow students, your family and everyone else safe.” York University or the University of the West of Scotland do not mention false negatives at all (but do mention the risk of false positives, the latter saying “that they do not pick up all the same infections that PCR tests do. This is why we recommend two tests, ideally three days apart”). Some universities have updated their information, such as Edinburgh University, which says: “Repeated testing reduces the risk of a false negative result, and therefore reduces the risk of infecting others, although this does not eliminate the risk entirely.” Glasgow University still says that negative testing should give “confidence and safety.” I am not sure why we can’t straightforwardly tell students that we think the test may give a false negative result, perhaps half the time, and ensure they do not rely on it to feel safe.
The lack of independent oversight, scrutiny, quality assurance, or plans for evaluation of the benefits and harms of the programme means that we may not find out how effective it has been until we have done needless harm. If the UK National Screening Committee is continued to be overlooked, the UK urgently needs an independent Covid Mass Testing Committee, composed of public health physicians, epidemiologists, general practitioners, and patient and public representation, to ensure we do not continue to waste money and mislead citizens.
Margaret McCartney is a GP partner, Glasgow.
Competing interests: MMC is a senior fellow for evidence and values at the RCGP, and a freelance writer and broadcaster who also receives royalties for three books. She gives a small amount regularly to Keep our NHS public and is honorary fellow at the CEBM Oxford.
- Preliminary report from the Joint PHE Porton Down & University of Oxford SARS-CoV-2 test development and validation cell: Rapid evaluation of Lateral Flow Viral Antigen detection devices (LFDs) for mass community testing 8/11/20 https://www.ox.ac.uk/sites/files/oxford/media_wysiwyg/UK%20evaluation_PHE%20Porton%20Down%20%20University%20of%20Oxford_final.pdf
- NHS England. Lateral flow antigen test FAQs. 16/11/20 https://www.england.nhs.uk/coronavirus/wp-content/uploads/sites/52/2020/11/C0873_ii_Lateral-flow-antigen-test-FAQ_16-Nov.pdf
- Adherence to the test, trace and isolate system: results from a time series of 21 nationally representative surveys in the UK (the COVID-19 Rapid Survey of Adherence to Interventions and Responses (COSTAIR). Smith LE et al. https://www.medrxiv.org/content/10.1101/2020.09.15.20191957v1.full.pdf
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- UK Diagnostic contracts. https://bidstats.uk/tenders/?q=diagnostic&source=ojeu#739901439-738394166-55
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