Making Sense of Screening
Screening tests can cause harm. This guide helps you to make sense of claims about screening for health conditions.Key Concepts addressed:
Fortunately, Sense About Science have written a guide to screening. In the guide, scientists, clinicians and medics explain that screening:
- rarely benefits all sections of the population.
- can have negative effects, so it needs to be targeted at those most likely to benefit.
- can identify some of the people who have a disease but it cannot prevent disease.
- cannot give you a ‘yes’ or ‘no’ answer and an ‘all clear’ does not mean you will not go on to develop the disease.
- screening tests differ from diagnostic tests.
Find out more:
The new 2015 edition of the guide Making Sense of Screening is published by Sense About Science with the kind assistance of the Institute of Biomedical Science and The Royal College of Pathologists.
Contributors to the guide: Michael Baum, Susan Bewley, Michael Fitzpatrick, Danielle Freedman, Peter Furness, Hedley Glencross, Síle Lane, Anne Mackie, Margaret McCartney, Joe O’Meara, Angela Raffle, Hazel Thornton, Ian Watson and Caroline Wright. Further details about the contributors can be found in the guide.
Read more in Testing Treatments
Testing Treatments draws on various disease examples to show why earlier diagnosis can be but is not always better; why many types of screening are of no, or uncertain, benefit; and how the benefits of screening have often been oversold and the harms downplayed or ignored.
Screening healthy people should never be undertaken lightly: there are always important downsides that should make us cautious.
Screening is a medical intervention. Not only that, the offer of screening is in itself an intervention. Even someone who chooses to decline screening will be left with a nagging doubt about whether they have made the ‘right’ decision – that is human nature. Not being offered screening in the first place is very different.
At best, screening should only be offered to the healthy people it seeks to reassure or treat if there is sound evidence that: (a) it will do more good than harm at an affordable cost; and (b) it will be delivered as part of a good quality and well-run programme.
Screening is much more than a ‘one-off’ test. People invited for screening need sufficient unbiased, relevant information so that they can decide whether to accept the offer or not – that is, they need to know what they are letting themselves in for.
One way of thinking about screening is like this: