Many DIY health tests could give false results, studies find

Many DIY health tests available on the high street are unfit for purpose and need better regulation, according to two new studies.

Self-tests for high cholesterol, vitamin deficiency, fertility and prostate problems are widely available in supermarkets and pharmacies, with the industry predicted to be worth £655m by 2030.

But researchers at the University of Birmingham have found that many tests could give users false results and were not always appropriate or safe.

The scientists reviewed 30 DIY health tests costing £1.89-£39.99, covering 19 different health conditions. These included vitamin D deficiency, blood sugar levels, thyroid function, prostate health, HIV, menopause and bowel cancer.

The two linked studies, published in the British Medical Journal (BMJ), rated 60% of the tests as “high risk” over concerns about the testing equipment, sampling process, or instructions and interpretation of the results. Only eight stated who the tests were suitable for, while fewer than half provided any information about accuracy. And of these, much of the evidence to back these claims was not publicly available or was of low quality.

With many tests recommending the user followed up with their GP or another healthcare professional regardless of the result, “this begs the question: ‘What’s the point of doing the test in the first place?’”, said Dr Clare Davenport, an associate clinical professor at the University of Birmingham and co-lead author of the studies.

“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,” she added. “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.”

The studies call for better regulation of DIY health tests to protect patients and prevent misuse. Prof Jon Deeks at the University of Birmingham and co-lead author of the studies said: “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 [Medicines and Healthcare products Regulatory Agency] will update the regulatory process to ensure self-tests are effective and safe for everyone.”

Joseph Burt, the head of diagnostics and general medical devices at the MHRA, said: “We take the safety of self-tests very seriously. We will review the evidence presented by the researchers and consider all allegations about device deficiencies.

“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 [Conformité Européene] or UKCA [UK Conformity Assessed] mark, read the instructions carefully and seek medical advice if they’re unsure about their result.”

Prof Kamila Hawthorne, the chair of the Royal College of GPs, said: “With the risk of false positives and negatives, and no offer of an interpretation of the results or aftercare, self-testing kits can mean patients experience a significant amount of stress and anxiety – prompting them to seek guidance from their GP to interpret any results.

“This not only negatively impacts our patients, but it can also intensify the enormous pressures that GPs and their teams are currently under. Commercial self-testing kits should not default to NHS general practice as the provider for next steps and aftercare, unless the test was initiated in primary care or as part of a commissioned NHS service.”