Are you someone who purchases and uses medical self-testing kits? If so, some just-published research suggests caveat emptor may be in order.
Self-testing is increasingly popular, especially since the Covid-19 epidemic, when lateral flow tests allowed ubiquitous home testing for the infection.
However, two studies published in the British Medical Journal have found that many self-tests are unfit for purpose and need greater regulation to ensure they are safe and reliable.
In the first comprehensive studies into the issue, researchers at the University of Birmingham reviewed 30 self-tests bought from local supermarkets, pharmacies and health-and-wellbeing shops. The tests covered 19 different conditions, including vitamin D deficiency, blood sugar, thyroid function, prostate health, HIV, menopause and bowel cancer.
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Of the 30 tests, just 14 made any statement about test accuracy, only eight provided information on the box about who should or should not use the test and only seven indicated what action to take after the result. Only 16 tests explicitly stated they were for screening, diagnosis or monitoring, while nine did not indicate the symptoms or risk factors for their use.
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However, nearly all tests (27 out of 30) recommended follow-up with a healthcare professional if results were positive or abnormal. Performance claims were made for 24 tests, with more than half claiming 98 per cent accuracy or higher. Yet, much of the evidence to back these claims was not publicly available or was of low quality, which the authors say also raises ethical concerns.
The researchers rated 18 of the tests as “high risk” over concerns about the testing equipment, sampling process or instructions and interpretation of the results, while use of the tests as advertised was judged contrary to evidence-based guidance for 11 of the 19 conditions studied.
Since collecting their initial sample of tests in 2023, the researchers have continued to track the market – and it’s flourishing. A repeat search of the same geographical area in December 2024 identified 63 tests, twice as many as the previous year, many of them clones of existing self-tests, rebranded and sold under different names by a range of distributors. And while the study was UK based, the tests all had CE marks – a certification mark to signify that products have met essential European standards – making the results relevant in an Irish context.
In the Republic, the Health Products Regulatory Authority (HPRA) assesses self-testing kits, which are classified as in-vitro diagnostic tests. It advises only purchasing products with a CE mark and for consumers not to rely on the tests alone. No self-testing is 100 per cent reliable, it says, pointing out that a number of factors may interfere with or affect test results, including medicines and dietary supplements.
An example of the problems with the self-testing kits identified by the BMJ is illustrated by one marketed for the diagnosis of “chronic kidney injury”. The test, which looks for the presence of protein in the urine, had the most usability issues of all the tests examined. There were significant sampling challenges and unclear result interpretation, with faint colour reference charts making results hard to read.
Readers may wonder if there is an element of medical paternalism at play here. After all, when home pregnancy tests were made available, some doctors argued that women should not be trusted to use them. But an accompanying BMJ editorial states that “giving people access to information and tools to understand their health is not in itself inherently problematic”.
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“Empowering individuals to take an active role in their health is an important goal, but if self-tests are to be sold directly to the public, they must be supported by high quality evidence, robust regulation, trustworthy public information, and clear pathways for interpretation and follow up,” it concludes.
For consumers here, the BMJ studies suggest a need for closer co-operation between the HPRA and the European Commission to ensure the CE marking system is fit for purpose.
