Concerned about a growing industry in DIY health testing and an increasing number of healthy people paying for a range of health checks to discover what diseases might lie in wait for them in the future, a UK consumer health charity has teamed up with other health professionals to warn the public about the potential dangers.
The charity Sense about Science, a group that describes itself as working “with scientists and civic groups to promote evidence and scientific reasoning in public discussion”, has produced a leaflet called “Making Sense of Testing” which, according to one of its collaborating organizations, the Association for Clinical Biochemistry:
“Challenges the increasingly promoted idea that testing healthy people for hidden diseases is a good idea”.
The new leaflet, whose publication was announced earlier today, 11th March, gives the other, less attractive and often overlooked side of the truth about health screening said the Association, who also teamed up with the Royal College of Pathologists and a policy, research and education group, the PHG Foundation charity, to produce the document.
Although to anticipate and deal with disease by discovering whether one has elevated risks or early signs seems like a good idea in principle, in practice testing healthy people can cause unnecessary alarm and give false reassurance.
The leaflet asserts that:
- Most health screening tests are not designed for use on healthy people and do not accurately predict the types of diseases you are likely to get in the future.
- Testing for a disease before you have any symptoms can harm you in ways you may not have thought about.
- Indeed some health tests produce “false positives”, that is suggest diseases you will most likely never have.
- There is very little research and insufficient regulation on what health checks claim to do for you.
- Diagnosis is not a simple process, and relies on a complex mix of clinical experience, research, examination of symptoms, and your context. An experienced health professional takes all these factors into account when advising you which tests to go for.
- DIY and home testing kits and full body scans do not usually give information that is clinically useful.
- The growing practice of genetic testing for healthy people concerned to discover their risk factors is based on very little preliminary research and the data produced this way is considered too scanty for use in evidence-based medicine.
Calling on UK regulators to tighten control of an industry that is currently worth about 99 million pounds a year, the leaflet comes in the wake of an investigation by the UK government’s Committee on Medical Aspects of Radiation in the Environment (Comare) last December that found people may be putting themselves at increased risk of developing cancer by having unnecessary scans. The Committee said the government should stop private firms offering body scans involving radiation direct to the public.
One area that appears to be generating growing interest is the biomarker test or genetic test that seeks to find out if you have an elevated risk of a disease because you have a particular DNA sequence or raised level of a chemical in your blood, like cholesterol.
These are are being offered by private firms, sometimes asking you to send samples in the post, where environmental conditions in a sorting office or mailbag cannot be guaranteed and may alter the chemistry of the sample and the validity of any results.
Apart from these non-laboratory conditions, there are other reasons why doing your own biomarker or genetic test could cause you unnecessary worry and anxiety, or even mislead you. All a marker test can do is find out if you carry a particular genetic sequence or have an elevated level of a chemical. It can’t tell you with any certainty what this means in practice, how likely it is that a disease will develop, which may depend on a whole range of other factors from lifestyle to what other conditions are present.
Dr Alastair Kent, Advocate and Director of the Genetic Interest Group described maintaining that this or that gene sequence leads to this or that risk factor as potentially inadequate science, explaining that before reliable predictions can be made, further work may be necessary. He said:
“A result in itself does not provide much of the information needed; it’s an incomplete basis for future planning. It does not tell you when or how quickly symptoms will start to show or which aspects of the condition will be most difficult to manage.”
Kent said that knowing the family history helps understand the former, and counselling helps with the latter.
“As with other areas of testing in medicine, the print-out from the analytical process is an aid to clinical judgement, not a replacement,” added Kent.
The plus side of a growing DIY health screening industry is that it has the potential to help people take more responsibility for their own health, increasing knowledge about one’s own health risks is empowering, but the potential downside is that the process itself also introduces health risks, many of which, as this leaflet reveals, may be obscured by the marketing hype.
Click here to download Sense about Science “Making Sense of Testing” leaflet (PDF).
Sources: Sense about Science, Association for Clinical Biochemistry, BBC News.
Written by: Catharine Paddock, PhD