In the world of health and medicines, screening refers to testing for conditions and diseases before there are any signs or symptoms - such as Pap smears for cervical cancer.
Screening falls under the banner of preventative medicine because you prevent future problems, so it's sometimes called preventative screening.
Here, CHOICE explains the issues with the following screening services, which are being offered directly to consumers without a medical referral:
Government-funded screens and tests vs direct-to-consumer screening
The government funds various screens and tests recommended for people at various ages and life stages, as well as general health indicators such as blood pressure, blood sugar and blood cholesterol levels. The government funds these tests because the health benefits for Australians and health system cost savings are calculated to outweigh the costs of supplying the tests.
But advances in medical technology and lower costs of equipment have seen many common diagnostic procedures and technologies being turned to screening for diseases and conditions in people without any symptoms.
By offering these services directly to consumers, both patients and service providers can bypass patients’ regular doctors and other health professionals. However, while applauding this proactive approach to looking after health, many medical professionals are concerned about the outcomes of the tests.
The main problem with such screening is that it may provide false reassurance that there are no problems, with implied permission to carry on as normal, even if that includes risky lifestyle and behaviours (diet, alcohol consumption, inactivity and so on). Or, it may find something suspicious, which will be followed up by invasive testing, accompanied by stress and anxiety that turns out to be unfounded.
On the other hand, a small percentage of people will benefit from the early detection of a disease or condition they were completely unaware of, potentially saving lives. This small payoff against a huge cost isn't enough to make the government bean-counters recommend the screens to everyone, but individuals who can afford it may feel the potential benefits outweigh the risks.
DIY genetic testing
There are many legitimate uses of genetic testing, which traditionally have been carried out through a private doctor or the public hospital system.
Medical genetic testing usually requires referral from a medical practitioner as well as pre- and post-test counselling, and a majority of tests occur through the public hospital system with geneticists and counsellors on hand. The patient must have the purpose of the test and the implications for themselves and their family explained, and provide informed consent. Medicare covers the cost of some genetic tests.
Genetic testing can be used:
- To predict an individual’s risk of disease when there is a family history of it. An example is the BRCA1 or BRCA2 gene mutations that indicate increased risk of breast and ovarian cancer, allowing potential action such as more frequent screening (mammograms) or risk reduction surgery (such as a preventative double mastectomy).
- To predict treatment response – for example, certain gene mutations in forms of cancer (breast, colon and melanoma) indicate susceptibility to particular treatment drugs. These drugs may be expensive or have undesirable side effects and shouldn’t be used when patients are not likely to benefit.
Now consumers can undertake their own testing by buying kits online, providing a DNA sample from the comfort of their own home, posting it off to a lab and finding out all manner of genetic information, such as:
- ancestry (for establishing paternity, for example)
- genetic quirks (sneezing when you look at a bright light)
- talents (athletic proclivities), and
- health information (susceptibility to diseases and conditions).
It’s this direct-to-consumer genetic testing, which bypasses the normal checks and balances of the health system testing, that’s raising concerns.
Should I get a DNA test?
Concerns raised by doctors and other health professionals include:
- Companies doing testing may be located offshore and not follow the same stringent test procedures and interpretation or analysis of Australian laboratories. This may mean inaccurate, unclear or misleading results.
- GPs are under no obligation to interpret, accept or act upon results of these genetic tests. If they’re inaccurate, unclear or misleading, the GP is liable.
- There may also be privacy issues, where privacy laws in other countries are different to our own. Some people get around this by providing a false name.
- Any information you discover may also affect family members, so consider the implications and how you share information.
- Genes don’t tell the whole story. Even if you have a genetic predisposition to certain health problems, such as type 2 diabetes or obesity, your lifestyle can determine whether genes get a chance to act.
- For now only a small fraction of the genetic contribution to common diseases has been identified, so a genetic profile won’t give you the big picture.
- If you have a predictive genetic test or a test for a condition or disease for which you have no symptoms, you have a duty to inform life insurers if applying for a new policy or changing an existing one.
- Some clinics are offering less well-established tests for commercial benefit. For example, some natural medicine clinics will conduct DNA testing to determine special nutritional needs you may have, then helpfully sell you the supplements to meet these needs, which may or may not be real.
The Human Genetics Society of Australasia (HGSA) encourages consumers considering DNA testing to discuss this with their healthcare provider, consider the potential negatives, and, should they decide to go ahead, choose a test provider that abides by practical and ethical principles based on best practice.