Is anyone normal?
Whole-body CT scans
Among the tests on offer at private clinics are whole-body computed tomography (CT) scans to look at head, neck, chest, abdomen, and pelvis. They are offered directly to the public, and usually done without reference to the person’s general/primary care practitioner.
Whole-body scans are often promoted as the way to keep one step ahead of possible illness, with the premise that a ‘normal’ result will be reassuring. Not only are these scans expensive, but also there is no evidence that any overall health benefit is achieved by doing these tests in people without symptoms or signs of disease. Moreover, the radiation exposure is considerable – as much as 400 times more than a chest X-ray. So much so that in 2007 the UK’s Committee on Medical Aspects of Radiation in the Environment (COMARE) strongly recommended that ‘services’ offering whole-body CT screening of asymptomatic individuals should discontinue to do so. In 2010, after consultation, the Government announced its intention to introduce tougher rules for using whole-body scans.
Similarly, the US Food and Drug Administration has warned the public that these scans have no proven benefits for healthy people, commenting ‘Many people don’t realize that getting a whole body CT screening exam won’t necessarily give them the “peace of mind” that they are hoping for, or the information that would allow them to prevent a health problem. An abnormal finding, for example, may not be a serious one, and a normal finding may be inaccurate.’ [23, 24, 25]
Striking a balance
Striking a balance between over-zealous trawling for disease and failing to identify those people who may benefit from early detection is never going to be easy, and will inevitably lead to unpopular decisions. All healthcare systems need to use their resources thriftily if the whole population is to benefit.
This fundamental principle surely means that screening programmes must not only be based on sound evidence when they are introduced but also kept under review to check whether they are helpful as more evidence accrues and circumstances change. A serious consideration is whether screening programmes should be offered to large sectors of the population or more targeted towards those at high risk of a condition.
More: References (Section 4)
Review of Key points
- Earlier diagnosis does not necessarily lead to better outcomes; sometimes it makes matters worse
- Screening programmes should only be introduced on the basis of sound evidence about their effects
- Not introducing a screening programme can be the best choice
- People invited for screening need balanced information
- The benefits of screening are often oversold
- The harms of screening are often downplayed or ignored
- Good communication about the benefits, harms, and risks of screening is essential
Next Chapter: Dealing with uncertainty about the effects of treatments