Better information and regulation are essential to protect consumers from potential harms of tests advertised directly to consumers, argue experts in The BMJ today.
Emma Gram at the University of Copenhagen and colleagues warn that consumers are at risk of buying products that do more harm than good and say the public needs high quality information and effective communication to protect consumers from unbalanced and misleading marketing.
Advances in diagnostic technology and digital health have increased the variety and volume of direct-to-consumer (DTC) tests, ranging from self-test kits and multicancer detection tests to testosterone tests and food sensitivity tests.
Sales of these tests have surged from $15m in 2010 to $1.15bn in 2022 in the United States alone, but no dedicated regulatory framework exists to govern the appropriate use of these emerging products.
For example, they point to poor accuracy of tests to indicate menopause or chance of conceiving, which may provide incorrect or misleading information to women about fertility or symptoms.
They explain that that, while the availability of self-testing kits may encourage undertested communities such as key affected populations of sexually transmitted infections to better access testing, they say inaccurate tests may not be sufficient to rule out infection - any false positive results can cause unnecessary follow-up consultations and further testing, while false negative results would provide false reassurance, and therefore delay treatment.
And they warn that information provided in instructions, packaging, and advertising is sometimes incomplete, misleading, or even false, giving consumers false premises for decisions about their health.
Clinical tests marketed for assessing "wellness" such as hormone levels may also carry important harms, they write. Results may trigger over-testing, distress associated with abnormal results that are not clinically important, or lead to unnecessary use of non-evidence based supplements and treatments, which can carry significant health risks such as fertility and cardiovascular problems.
The marketing of these tests also target healthy people, who are least likely to benefit from testing.
The potential harms of multicancer detection tests could also be substantial, they add. These tests, currently being marketed and sold in the US, claim to detect over 50 types of cancer before symptoms have occurred. But Gram and colleagues argue that they are more likely to detect late stage cancers, causing significant harm without accompanying benefits.
They acknowledge that DTC tests may be beneficial in some cases, but say studies are yet to demonstrate that their use leads to better health outcomes.
To address potential consumer harms, professional organisations are calling for tests to have clear interpretations and results, and for patients to have clear information about when self-testing is recommended and when it is not. However, without official policy directives and regulation of commercial suppliers that operate outside the healthcare system, these changes are slow to happen.
"Clearly, current regulatory frameworks are inadequate in responding to the new ways in which DTC tests are being sold and used," note the authors.
"Commercial suppliers should prove product benefit for their consumers, including clearly defining appropriate targeted populations of tests to avoid harmful misinterpretation," they write. "In addition, industry and regulatory bodies should engage in broader concepts of harm such as financial burden, psychological and physical harm, overdiagnosis, and ineffective diagnosis associated with DTC testing."
Finally, they say "more research on consumers' perspectives and values in self-testing is critical for improving user centred practice, benefit, and safety."
