Influencers on Instagram and TikTok are misleading us about controversial medical tests

Kim Kardashian recently told her Instagram followers she’d had a full-body MRI and said the scan can be "life saving", because it can supposedly spot disease at the earliest stages, before any symptoms appear.

What her post did not make clear is that there’s no evidence this costly scan benefits healthy people. Nor did it highlight the potential downsides, such as unnecessary diagnoses and treatments that aren’t needed.

That post prompted us to take a closer look at what influencers and high-profile accounts are saying online about medical tests.

In a new study published today in JAMA Network Open, we examined almost 1,000 Instagram and TikTok posts about five widely promoted tests - including the full-body MRI - that can, for healthy people, do more harm than good.

Overall, we found that the vast majority of posts gave a highly misleading picture.

5 controversial tests

Before turning to our results, it helps to understand the five tests included in our study.

Each of these tests can be useful for certain people in particular clinical circumstances. But for people who are generally well, all five carry a risk of overdiagnosis. Overdiagnosis means identifying a condition that would never have gone on to cause symptoms or problems.

Overdiagnosis commonly leads to overtreatment - exposing people to needless side effects and worry - and it also wastes health-system resources.

To illustrate the scale, estimates suggest 29,000 cancers each year are overdiagnosed in Australia alone.

Overdiagnosis is a worldwide issue, and it is fuelled in part by healthy people undergoing tests like these. They’re often sold as early screening and framed as a way to "take control" of your health - even though most healthy people do not need them.

Here are the five tests we assessed:

The full-body MRI scan is marketed as checking for up to 500 conditions, including cancer. Yet there is no proven benefit for healthy people, alongside a genuine risk of unnecessary treatment triggered by "false alarm" findings.

The "egg timer" test (more formally, the AMH or anti-müllerian hormone test) is frequently and incorrectly promoted as a fertility test for healthy women. Although it may be helpful for women in a fertility clinic context, it cannot reliably forecast a woman’s chances of conceiving or when menopause will begin. A low result can, however, heighten fear and anxiety and may push people towards unnecessary, expensive fertility treatment.

Multi-cancer early detection blood tests are being aggressively promoted as the "holy grail of cancer detection", with claims they can screen for more than 50 cancers. In reality, clinical trials are still far from complete, and there is not yet strong evidence that any benefits will outweigh the harms of unnecessary cancer diagnoses.

The gut microbiome test (using a stool sample) promises "wellness" through early detection of a wide range of conditions, from flatulence to depression, despite a lack of good evidence that it helps. There is also concern these results can drive wasted resources.

Testosterone testing for healthy men is not backed by any high-quality evidence. There are concerns that direct-to-consumer advertising encourages men to test and then use testosterone replacement therapy when it isn’t needed. Testosterone replacement therapy comes with potential harms, and its long-term safety - including effects on heart disease and mortality - remains largely unknown.

What we found

Working with an international team of health researchers, we analysed 982 posts about these tests across Instagram and TikTok. We included posts from influencers and account holders with at least 1,000 followers, and some had followings in the millions. Altogether, the creators in our sample had close to 200 million followers.

Even allowing for bots, that represents enormous influence (and likely understates their real reach beyond followers).

Most posts were misleading because they did not even acknowledge that harm can arise from taking these tests. Specifically, we found:

• 87 percent of posts highlighted test benefits, while only 15 percent referred to potential harms
• only 6 percent of posts mentioned the risk of overdiagnosis
• only 6 percent of posts discussed any scientific evidence, while 34 percent relied on personal stories to encourage the test
• 68 percent of influencers and account holders had financial interests in promoting the test (for example, a partnership, collaboration, sponsorship, or selling it for their own profit in some way).

When we looked more closely, we found posts from medical doctors were slightly more even-handed. They were more likely to mention harms, and less likely to adopt a strongly promotional tone.

Like all research, our study had limitations. For instance, we did not examine the comments under posts. Those discussions could offer additional insight into what information is being shared about these tests, and how social media users interpret it.

Even so, our results add to the growing evidence that misleading medical information is common on social media.

What can we do about it?

Specialists have suggested a variety of responses, including “pre-bunking” approaches - proactively teaching the public about common tactics used to spread misinformation.

But measures like these often shift the burden onto individuals. With the sheer volume of health content people must sift through on social media, that’s a substantial demand - even for those with good health literacy.

What is urgently required is stronger regulation to stop misleading information being produced and circulated in the first place. This matters even more as social media platforms, including Instagram, are moving away from fact-checking.

In the meantime, keep in mind: if an influencer’s claims about a medical test sound too good to be true, they probably are.

Brooke Nickel, NHMRC Emerging Leader Research Fellow, University of Sydney; Joshua Zadro, NHMRC Emerging Leader Research Fellow, Sydney Musculoskeletal Health, University of Sydney, and Ray Moynihan, Assistant Professor, Faculty of Health Sciences & Medicine, Bond University

This article is republished from The Conversation under a Creative Commons licence. Read the original article.