Direct-to-consumer diagnostic tests ‘often harmful’

By Geir O'Rourke

1 Feb 2024

Most diagnostic tests sold directly to consumers in Australia have low clinical utility, while also potentially causing harms of overdiagnosis and false positives, a review has found.

The study of nearly 500 pathology assays commercially marketed for purchase by Australian consumers, highlights the need for stronger regulation and public education on the subject, its investigators say.

Some 484 tests targeting 103 unique medical conditions, analytes or test products were included in the analysis, with only 11% assessed as having potential clinical utility.

A further 31% were determined to have ‘limited clinical utility’, while 42% were non-evidence-based commercial ‘health checks’ and 17% used methods or targeted conditions not recognised by the general medical community, the researchers found.

Concerningly, of the products identified, 56% did not state that they offered pretest or post-test consultation, and 51% did not report analytical performance of the test or laboratory accreditation, they reported in BMJ Open (link here).

“The risks and harms of ordering direct-to-consumer tests, which the TGA review identifies as being particularly relevant for cancers and genetic testing, is that professional guidance and clinical monitoring is lacking,” they noted.

“As the balance of harms and benefits of predictive genetic testing is still unclear for many chronic conditions, the call is for an ongoing development of guidelines, professional knowledge and practice in this field, to ensure caution and ethical considerations when offering such tests to asymptomatic, healthy individuals.”

Beyond that were the financial concerns, with products in the study costing a mean of $198 and the most expensive test priced at an eye-popping $1947 for an antigen leukocyte antibody (ALCAT) study to assess food sensitivities.

The latter was an unproven test of the sort typically associated with on-sale of non-evidence-based treatments also known as “disease mongering”, according to the authors.

Moreover, greater than 40% of the tests found in the study aimed to assess normal, everyday functions such as sleep, ageing, physical activity and hormone levels, they said.

“The emerging wellness industry relies on the material data from these test results to support a pipeline of justifying and promoting the consumption of nutritional supplements and dietary advice,” they added.

“However, testing healthy populations without clear clinical justification will only normalise the notion that people are ‘sick until proven healthy’.”

“The downstream consequence of this ‘low-value’ practice is the triggering of unnecessary medical waste, and more opportunity for incidental and unnecessary diagnoses.”

On the other hand, the 11% of tests found to have clinical utility did show there could be a place for direct-to-consumer products, according to the authors, who noted the most common examples found in the study were for sexually transmitted infections, for which stigma contributed to barriers to care.

Interestingly, these STI tests tended to come in the form of home self-testing kits which were lower in cost compared with direct accessed pathology tests and more likely to report test accuracy, the team noted.

They concluded: “At the policy and regulation level, higher standards of test quality and regulation are needed to support informed decision-making for consumers.”

“Under the new European In Vitro Diagnostic Regulation there are increasing requirements for companies to provide data to the regulator not just on the quality and analytical performance of tests but also evidence on the clinical performance of the devices, as well as a need for post-market surveillance on the performance of the tests.

“Similarly, in Australia, direct-to-consumer tests… should fall under the same scrutiny and regulation before they are allowed to enter the online market.”

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