Can we help the public understand the concept of ‘overdiagnosis’ better by using a different term?

Authors: Alex Ghanouni, Cristina Renzi & Jo Waller

We have previously written about ‘overdiagnosis’ – the diagnosis of an illness that would never have caused symptoms or death had it remained undetected – and how the majority of the public are unfamiliar with the concept and find it difficult to understand. We have also looked at the various ways that health websites describe it in the context of breast cancer screening; we previously found that most UK websites include some relevant information, in contrast to the last similar study from 10 years ago. This led us to think about how it might be possible to better explain the concept to people. Although ‘overdiagnosis’ is the most commonly used label, its meaning is probably difficult to infer if people are unfamiliar with it (and most people are). We wanted to test whether other terms might be seen as more intuitive labels that would help communicate the concept to the public.

We carried out a large survey in which we asked around 2,000 adult members of the public to read one of two summaries describing overdiagnosis. These summaries were based on information leaflets that the NHS has already used extensively in England. We asked people whether any of a series of possible alternative terms made sense to them as a label for the concept described and whether they had encountered any of the terms before.

What did we find?

A fairly large proportion of people (around 4 out of 10) did not think any of the seven terms we suggested were applicable labels for the concept as we described it. We also found that no single term stood out as being seen as particularly appropriate. The term most commonly endorsed (“unnecessary treatment”) was only rated as appropriate by around 4 out of 10 people. Another important finding was that around 6 out of 10 people had never encountered any of the terms we suggested and that the most commonly encountered term (“false positive test results”) was only familiar to around 3 out of 10 people. You can read the full paper here.

What were our conclusions?

We were disappointed that we did not find a term that was clearly considered to be an intuitive label for the concept of overdiagnosis. However, this was not entirely surprising because we know from several studies that it is unfamiliar to most people. It is not a given that this will always be the case: Organisations like the NHS and health charities are continually telling the public about overdiagnosis in various ways and if the concept becomes more familiar and better understood, people may be more inclined to identify a term that makes sense and which can then be used to communicate the concept. It is also possible that terms other than the 7 we looked at might already be suitable. Since the terms we looked at were generally unfamiliar, one recommendation we can make in the meantime is that it might be better to avoid specific labels like “overdiagnosis” when communicating the issue to people; explicit descriptions might be more helpful.