Most UK high street self-tests fall short on accuracy and safety warnings

Many self-tests available on the UK high street are unfit-for-purpose and need much greater regulation to ensure they are safe and reliable, conclude two studies published by The BMJ today.

The findings show that most self-tests lack essential information about who should use them, how to interpret the results, and what actions to take next. Some also contradict evidence-based guidance, "creating risks for misinterpretation and inappropriate healthcare decisions," say the authors.

Self-testing is increasingly popular, with a wide range of tests available to UK consumers without needing healthcare professional involvement. The UK market for self-tests is expected to reach a projected revenue of £660m by 2030.

Concerns have been raised about the quality, appropriateness and safety of self-test kits, but no comprehensive study has examined what is currently available on the UK high street.

To address this, 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.

Of the 30 tests, only 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. However, nearly all tests (27 out of 30) recommended follow-up with a healthcare professional if results were positive or abnormal, and 14 regardless of the result.

Performance claims were made for 24 tests, with over half (14; 58%) claiming 98% 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 (60%) 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.

The tests they found had the most issues were all distributed by one of two companies, Newfoundland and Suresign. They include Menopause (FSH) Rapid Test (Suresign) and FSH Rapid Menopause Test Midstream (Newfoundland); Microalbuminuria Rapid Test Kit (Colloidal Gold) for the diagnosis of chronic kidney injury (Newfoundland); Vitamin D Rapid Test Cassette (Newfoundland) and Vitamin D Test (Suresign); and TSH Rapid Test Cassette (Newfoundland) to detect underactive thyroid.

The authors acknowledge that the study sample was restricted to the Birmingham area and that their assessments were restricted by the lack of access and poor reporting of documentation provided by manufacturers. However, they say this is a robust, reliable evaluation of self-tests available to the UK public.

As such, they argue that the current UK self-test market fails to support informed use and the effectiveness of regulatory oversight is a serious concern. "There is an urgent need for coherent guidance and improved regulation to protect both individuals and healthcare systems from misuse and misinformation," they conclude.

Poor quality tests can cause real harm to patients, say doctors in a linked editorial. Tools must be fit for purpose, they write, and the NHS should not be expected to provide a "free" follow-up service for companies offering inappropriate, oversold, and low value tests.

"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," they conclude.

In a linked feature, Bernie Croal, president of the Royal College of Pathologists, emphasises the knock-on effects for the NHS. "There are significant risks to patients when poor quality tests are carried out inappropriately, with both false reassurance and unnecessary consequences for the NHS to repeat tests or take additional action," he tells The BMJ.

Since collecting their initial sample of tests in 2023, the researchers have continued to track the market - and it's booming. 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.

There is an urgency for regulatory action and to harness the potential of these tests, says Professor Jon Deeks at the University of Birmingham. "Self-tests have a clear potential to improve public health. However, for them to be beneficial and not harmful, they must be proven to be accurate, easy to use, and supported by clear instructions. We hope the MHRA will update the regulatory process to ensure self-tests are effective and safe for everyone."