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Thinking of buying a medical self-test kit? Read this first

Growing trend of home tests cover a range of issues from fertility to coeliac disease, but are they reliable?


Think of a health concern you might have and the chances are there’s now an associated home test kit available, mostly online. A sexual health worry? Check. Fertility concerns? Check. Fear of elevated cancer risk? Check. Possible nutritional deficiencies? Check.

But how advisable is this emerging trend, particularly when pushed by commercial interests?

How do you distinguish helpful tests from unnecessary or even potentially dangerous ones? Are the “worried well” being sucked in to spending money where there’s no need?

Home test kits fall into two broad categories. The first is where you can see the results for yourself, such as with antigen and pregnancy tests. For the second you use the kit to collect samples that have to be sent to a laboratory for processing.

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As has been debated over antigen tests, would wider availability of self-testing empower people in looking after their own health? And/or does it pose a risk by, for instance, inadvertently reassuring people who should have a cause for concern?

“Home self-testing has a usefulness in certain cases,” says Dr Nóirín O’Herlihy, a GP in Mallow, Co Cork, and assistant medical director of the Irish College of General Practitioners (ICGP). For example, GPs encourage participation in the Bowelscreen programme, which is aimed at people aged 60-69 to try to detect bowel cancer at an earlier stage.

She also acknowledges the HSE’s recently expanded home-testing service for sexually transmitted infections as a “successful initiative”. However, these programmes, she points out, are supported by appropriate selection of target groups and a clinical team is provided for follow-up.

“The concern with home self-testing without clinical support is that it may be inappropriate to perform the test to begin with and interpretation of the result is often difficult for non-healthcare professionals.”

O’Herlihy believes that the Covid-19 antigen tests are an “excellent example” of issues that can arise with home self-testing. “The ICGP continues to promote the message that as GPs we cannot diagnose Covid-19 without a PCR test and it is really important that everyone with any symptoms, even mild ones, self-isolate and await the results of a PCR test. Antigen tests have their place, but where symptoms are present a PCR test is required.”

If the pre-test probability of having a particular health issue is low then the chances of a false positive result arise, leading to anxieties, she says. If the specificity of the test is poor, ie the ability of the test to confirm whether or not you have the disease, there is a risk that people may be inappropriately reassured by a false negative result and not seek the care they need.

If the results of self-tests do raise patients’ concerns, naturally they may contact their GP, and that “may lead to inappropriate use of healthcare services, which at present are already very busy”, she says.

Some tests may not work properly, may not be intended for your condition, may only be for use by healthcare professionals or may even be fake

The remit of the Health Products Regulatory Authority (HPRA) extends to all self-tests, which are classed as in-vitro diagnostic medical devices. While self-tests may have a role to play, they should not be relied upon on their own, the authority warns in an advice leaflet for consumers (available to download on hpra.ie). "If you have any concerns about your health or a test result you should consult a healthcare professional."

As regards antigen tests, the HPRA says it is important to distinguish between those manufactured for a professional setting and those intended for use at home. The latter undergo an independent assessment on the suitability of the device design and instructions for use by the public. If the device is intended for self-testing, that fact must be clearly stated either on the label or on the instructions for use.

If you are thinking of buying any self-test, be it from a pharmacy, a supermarket or online, the HPRA advises that:
– You should purchase from a reliable source.
– Make sure that the device has a CE mark. All valid medical devices must bear a CE mark for the specific medical purpose claimed.
– Self-testing devices must also have a four-digit number to confirm that they meet important safety and design standards.
– Look for a European address. Medical devices that are CE marked and sold on the European market must have a registered business premises in Europe.

When buying tests online, “the risks associated with the device may be greater”, it says. While acknowledging that genuine tests are available online, others may pose a threat to health.

“Some tests may not work properly, may not be intended for your condition, may only be for use by healthcare professionals or may even be fake.”

Tighter European regulations on in-vitro diagnostic devices will be fully applicable from May 26th next, after a five-year lead-in time. They are changing the way manufacturers obtain the CE marking so that products can be sold on the European market.

A revised classification system will mean that in many more cases an independent body will be needed to assess products before they go on sale, instead of the self-certifying that was possible before.

Dietician Sarah Keogh acknowledges that people like to take nutrition-related "wellness" tests but, she says, "the problem is that it is not enough just to test for something, you have to be able to interpret the result".

For instance, somebody who gets a low reading for vitamin B12 might decide just to take a B12 tablet, whereas there are a few medical conditions that could be the cause, she says.

“You might have coeliac disease or Crohn’s disease or pernicious anaemia, in which case B12 supplements won’t do anything.” If you test for folate levels, find they are low and start taking folic acid tablets, “they mask a B12 deficiency”.

On the question of home-testing for coeliac disease, she says "flat out no way", on behalf of the Coeliac Society of Ireland, for which she is the in-house dietitian. She understands that sometimes people can become frustrated while waiting to reach a diagnosis through GPs and may look for a speedier option but she is adamant this is not the answer.

As a dietitian she will always do a “sweep” of nutritional tests for any client, as would a GP with blood tests, she points out. But in both cases, she and the GP will have talked to the person, got a sense of what was going on and picked a suite of appropriate tests, that should all be taken together rather than a random one.

Keogh also suggests that people need to ask themselves why they’re doing “wellness” tests. For individuals eating well and doing fine, there’s usually no reason for them to take these tests. On the other hand, “if you’re not feeling well, it’s ‘go to your GP to find out what’s going on’.”

Self-tests can be costly. “You can end up spending money on them and then, if the results indicate your levels are low,” she adds, “you still need to go to the doctor to run the same set of tests”.

Food intolerance is a diagnosis that needs to be made by a clinician or dietitian and it cannot be made based on a single blood test or other test method

There are pros and cons to the use of wellness checks, says O’Herlihy. The National Framework for the Integrated Prevention and Management of Chronic Disease in Ireland 2020-2025 funds GPs to identify individuals at high risk of diabetes of cardiovascular disease, who then have annual visits to the GP and practice nurse to address risk factors. However, the difficulty with a self-administered wellness test, she says, is that the person may not know which test to choose and if the results return as abnormal will likely need to contact a healthcare professional for advice.

If you’re considering buying a food intolerance test kit, the clear message from the HPRA is think again. Products being promoted as food intolerance tests cannot diagnose food intolerance and it advises members of the public not to act on the results of these tests without expert advice from a doctor or registered dietitian. “Food intolerance is a diagnosis that needs to be made by a clinician or dietitian and it cannot be made based on a single blood test or other test method,” it adds.

Most pharmacies stock some type of self-testing kits, such as pregnancy tests that are in routine use now as a reliable method for women to discover if they are expecting. Pregnancy tests are very accurate, certainly after six weeks, says pharmacist Kathy Maher, who is based in Duleek, Co Meath. "GP ones aren't any more accurate, they are just bought in bulk."

Her family pharmacy business would also sell ovulation predictor tests but “they are quite expensive and the evidence behind them isn’t compelling”. It really depends on the regulation of an individual woman’s cycle, she explains. “There is certainly no point in testing for ovulation day 11-14 if you have a 35-day cycle.” She has also had customers request drug-testing kits.

“We have been asked for these occasionally by parents, who have found something in their son or daughter’s room and want to check.”

As with all these types of products sold through pharmacies, a conversation at the time of purchase can, she says, help somebody not only get value for their money but also increase the likelihood of an accurate result, which reflects what’s actually going on for the individual.

However, sometimes it's the avoidance of upfront conversations that are part of the appeal of online home-tests, as well as the convenience. The Health Service Executive noted that 57 per cent of users during the piloting of home-test kits for sexually transmitted infections said they had never accessed sexual health services before.

The Irish company LetsGetChecked started out in 2015 with tests for sexually transmitted infections and now offers more than 30 test kits, spanning sexual health, men and women’s health, wellness and Covid-19. Ranging in price (€49-€249), these are all kits for taking samples at home, which are then sent to be processed in labs.

Results are promised within two to five days, through a personal, online account. If you have an “abnormal result” on any of their tests, a spokeswoman says its care team will be in touch via phone directly. “In the case you do not answer, we will send an email to you with an option to call us back to speak to a nurse.”

The majority of the company’s customers are based in the US, with testosterone and “male hormone advanced” tests being most popular with men, while tests relating to thyroid, female hormone and HPV most commonly sold to women. However, its bestseller continues to be a multiple-STI test kit.

Living through the coronavirus pandemic has forced changes in the way healthcare is delivered that might never have been envisaged. Undoubtedly, some have proved to be improvements and are here to stay.

Dr O’Herlihy says that while she is not aware of any guidelines for GPs that recommend the use of home self-testing to support their clinical decisions, “with an increase in demand for telemedicine it is possible that such tests may be used in the future”.

In difficult to reach groups, there may be a role, she adds. “For example, in the Netherlands, home self-testing for HPV is offered as part of their national screening programme for people who do not want to attend for a cervical smear.”

While home-testing may still be predominantly a case of “buyer beware”, State services are clearly weighing up its potential as another channel for delivering public health.

Read: Home tests for sexually transmitted infections