You can now order all kinds of medical tests online: Research shows this is (mostly) a bad idea

Many of us have done countless rapid antigen tests (RATs) over the course of the pandemic. Testing ourselves at home has become second nature.

But there's also a growing worldwide market in medical tests sold online directly to the public. These are "direct-to-consumer" tests, and you can access them without seeing a doctor.

While this might sound convenient, the benefits to most consumers are questionable, as we discovered in a recent study.

What are direct-to-consumer tests?

Let's start with what they're not. We're not talking about patients who are diagnosed with a condition, and use tests to monitor themselves (for example, finger-prick testing to monitor blood sugar levels for people with diabetes).

We're also not talking about home testing kits used for population screening, such as RATs for COVID, or the "poo tests" sent to people aged 50 and over for bowel cancer screening.

Direct-to-consumer tests are products marketed to anyone who is willing to pay, without going through their GP. They can include hormone profiling tests, tests for thyroid disease and food sensitivity tests, among many others.

Some direct-to-consumer tests allow you to complete the test at home, while self-collected lab tests give you the equipment to collect a sample, which you then send to a lab. You can now also buy pathology requests for a lab directly from a company without seeing a doctor.

What we did in our study

We searched (via Google) for direct-to-consumer products advertised for sale online in Australia between June and December 2021. We then assessed whether each test was likely to provide benefits to those who use them based on scientific literature published about the tests, and any recommendations either for or against their use from professional medical organizations.

We identified 103 types of tests and 484 individual products ranging in price from A$12.99 to A$1,947.

We concluded only 11% of these tests were likely to benefit most consumers. These included tests for STIs, where social stigma can sometimes discourage people from testing at a clinic.

A further 31% could possibly benefit a person, if they were at higher risk. For example, if a person had symptoms of thyroid disease, a test may benefit them. But the Royal Australian College of General Practitioners does not recommend testing for thyroid disease in people without symptoms because evidence showing benefits of identifying and treating people with early thyroid disease is lacking.

Some 42% were commercial "health checks" such as hormone and nutritional status tests. Although these are legitimate tests—they may be ordered by a doctor in certain circumstances, or be used in research—they have limited usefulness for consumers.

A test of your hormone or vitamin levels at a particular time can't do much to help you improve your health, especially because test results change depending on the time of day, month or season you test.

Most worryingly, 17% of the tests were outright "quackery" that wouldn't be recommended by any mainstream health practitioner. For example, hair analysis for assessing food allergies is unproven and can lead to misdiagnosis and ineffective treatments.

More than half of the tests we looked at didn't state they offered a pre- or post-test consultation.

Products available may change outside the time frame of our study, and direct-to-consumer tests not promoted or directly purchasable online, such as those offered in pharmacies or by commercial health clinics, were not included.

But in Australia, ours is the first and only study we know of mapping the scale and variety of direct-to-consumer tests sold online.

Research from other countries has similarly found a lack of evidence to support the majority of direct-to-consumer tests.

Four questions to ask before you buy a test online

Many direct-to-consumer tests offer limited benefits, and could even lead to harms. Here are four questions you should ask yourself if you're considering buying a medical test online.

1. If I do this test, could I end up with extra medical appointments or treatments I don't need?

Doing a test yourself might seem harmless (it's just information, after all), but unnecessary tests often find issues that would never have caused you problems.

For example, someone taking a diabetes test may find moderately high blood sugar levels see them labeled as "pre-diabetic". However, this diagnosis has been controversial, regarded by many as making patients out of healthy people, a large number of whom won't go on to develop diabetes.

2. Would my GP recommend this test?

If you have worrying symptoms or risk factors, your GP can recommend the best tests for you. Tests your GP orders are more likely to be covered by Medicare, so will cost you a lot less than a direct-to-consumer test.

3. Is this a good quality test?

A good quality home self-testing kit should indicate high sensitivity (the proportion of true cases that will be accurately detected) and high specificity (the proportion of people who don't have the disease who will be accurately ruled out). These figures should ideally be in the high 90s, and clearly printed on the product packaging.

For tests analyzed in a lab, check if the lab is accredited by the National Association of Testing Authorities. Avoid tests sent to overseas labs, where Australian regulators can't control the quality, or the protection of your sample or personal health information.

4. Do I really need this test?

There are lots of reasons to want information from a test, like peace of mind, or just curiosity. But unless you have clear symptoms and risk factors, you're probably testing yourself unnecessarily and wasting your money.

Direct-to-consumer tests might seem like a good idea, but in most cases, you'd be better off letting sleeping dogs lie if you feel well, or going to your GP if you have concerns.

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