23-07-2025
Shop-bought health tests not always fit for purpose, researchers warn
Off-the-shelf health tests for issues such as high cholesterol, vitamin deficiency, fertility and prostate problems may not be fit for purpose, researchers have warned.
A team from the University of Birmingham examined tests that people can buy in UK supermarkets, pharmacies and shops and which they then use at home.
They found the tests risked giving people the wrong result, could delay diagnosis, and most of them recommended follow-up with a doctor anyway, regardless of the result.
The researchers called for much tighter regulation of the sector, adding the NHS may face additional demand after people self-test.
They said: 'In the absence of guidance from healthcare professionals, individuals might use tests inappropriately or without a clear understanding of the implications of the results.
'False positive test results can lead to unnecessary anxiety, increased healthcare usage, and additional costs, whereas false negative test results may delay appropriate treatment or engagement with… screening programmes.
'Test errors can stem from inherent limitations in the accuracy of the test, as well as user-related issues such as sampling errors, incorrect processing, and difficulties in interpreting the results.'
However, the team said that in the future, home tests could have great potential for patient care.
The Medicines and Healthcare products Regulatory Agency (MHRA), which regulates medical products, said it would look at the findings.
Professor Jon Deeks, from the University of Birmingham, said: 'A plethora of new health self-tests have emerged in recent years and are available to buy from many high street supermarkets and pharmacies in the UK.
'While these kits have been approved for sale, they are not subject to the same stringent regulations as pharmaceutical products.
'Our recent research raises concerns about the suitability, accuracy and usability of many of the self-testing products available that require users to sample, test and interpret results themselves.
'In some cases, it is unclear how accuracy claims are supported, and there is no requirement of manufacturers to share the evidence behind these claims.'
Prof Deeks said the UK is looking at a 'new world' when it comes to self-testing, but there is more work to do to show claims made were robust.
He said much of the literature contained with tests was 'not easy to understand', while some of the results could lead to a 'wrong diagnosis'.
In one example, he said the self-tests for prostate-specific antigen (PSA) levels, a marker of prostate health, were fixed at a certain concentration level.
However, 'if you're age 70 you need to have your PSA done at a very different level to when you're 20', he said.
Self-testing is becoming increasingly popular, and the UK market for self-tests is expected to reach £660 million by 2030.
Overall, 30 self-tests costing £1.89 to £39.99 were included in the study, published in the British Medical Journal (BMJ).
The tests covered 19 different conditions, including vitamin deficiency, blood sugar levels, cholesterol, thyroid function, prostate health, HIV, menopause and bowel cancer.
Researchers said only eight of the 30 tests provided information about who should or should not use the test, while four specified the presence of symptoms.
External packaging on fewer than half of the tests (14) included any statement about their accuracy.
Meanwhile, 90% of the tests recommended follow-up with a healthcare professional if test results were positive or abnormal, while 47% recommended this if test results was negative.
Accuracy claims were made for 24 of the tests, including in pamphlets, and most (58%) claimed a performance of at least 98% accuracy, sensitivity or specificity.
However, the researchers said evidence supporting accuracy claims were largely unavailable or did not provide sufficient information for people likely to purchase the tests.
Prof Deeks said: 'Current regulations for the use of self-testing kits in a commercial setting are not adequately protecting consumers.
'Several of the self-test manufacturers refused to provide us with reports of their studies, which support their claims, stating that they were 'commercially confidential'.
'Legally, they do not need to share this information. However, for all matters of our health, it really is important that the evidence upon which health decisions are made is available and can be scrutinised.'
Dr Clare Davenport, clinical associate professor at the University of Birmingham, said: 'The wide range of off-the-shelf tests now available to the public are not endorsed by the NHS and evidence for their benefit is lacking.
'This is in contrast to well-established self-tests, such as pregnancy tests.
'We are worried that consumers concerned about their health and tempted by the convenience of buying a test over the counter may be harmed if they use these tests in the wrong way.'
Dr Davenport said the recommendation that people see a doctor anyway regardless of the result 'begs the question 'what's the point of doing the test in the first place?''.
Sue Davies, Which? head of consumer rights and food policy, said: ' Consumers should be careful with self-tests – they can be expensive, tricky to interpret and don't always come with an expert consultation to help you understand your results.
'It's also likely you'll need to follow up with your GP, so we'd always recommend involving them from the start if you have any particular health concerns.
'Most tests you'll need will be available for free on the NHS and your GP will also be able to speak to you about how you're feeling and spot any symptoms that might not show up on a test.'
While clinical trials and medicines must go through the MHRA, self-test devices are subject to checks by notified bodies.
A spokesman for Suresign, which provides three of the self-tests studied, said: 'We find this blanket condemnation of a small range of home tests available to be unreasonable and unprofessional, since they admit they are content with many of those examined.
'This is not a clinical approach to a highly scientific subject.
'They also did not confirm that the clinical studies related to our tests were supplied to them, as confirmed to us by the BMJ.
'Our detailed responses to their questions were not fully reflected in their article.
'They have implicitly criticised the professionalism of notified bodies appointed by the MHRA, when we find them to be very exacting in their audits.
'We are content our tests give the public access to healthcare screening not easily available with the NHS at the present time.'
Joseph Burt, MHRA head of diagnostics and general medical devices, said it would review the evidence and 'consider all allegations about device deficiencies'.
He added: 'We have strengthened post-market surveillance powers to monitor and act on concerns.
'These require manufacturers to actively monitor their products and report significant incidents to us, including for CE-marked self-tests.
'We're overhauling the medical device regulations to further strengthen standards for safety, usability and clinical performance and we're exploring new transparency measures such as requiring published summaries of clinical evidence.
'In the meantime, we strongly encourage anyone using a self-test to check for a CE or UKCA mark, read the instructions carefully, and seek medical advice if they're unsure about their result.'
