Breast cancer screening

Using data visualisation to explain risks – Breakthrough Breast Cancer

Case study contributed by Hannah Bridges, Health Content Specialist, HB Health Comms formerly of Breakthrough Breast Cancer

What was the project’s aim?

In 2013, Breakthrough Breast Cancer (now Breast Cancer Now) published an online guide to breast screening. Its development was challenging, as there had been heated debates surrounding the benefits and risks of breast screening in the media. Breakthrough wanted to produce a guide that was clear, balanced and informative, and that supported women aged 50 to 70 in making their own choice about whether to have a mammogram.

A crucial part of this was making sure that the key statistics on breast screening were clear and understandable.

We did this through two animations: one explaining how breast screening can save lives, and another explaining how screening can lead to over-treatment. These appear in Breakthrough Breast Cancer’s award-winning guide, Breast Screening: The Facts.

How did you research what format would work?

Hannah visual risk case studyThrough previous user testing of publications, we already knew that using icon arrays to explain statistics helped our audience to understand risk. Added to this, published best principles for communicating risk include using absolute numbers rather than percentages, and using a common denominator. So for example, saying that about one in eight women get breast cancer will be understood by more people than saying 13%.

Our thoughts were backed up by observing a three-day citizen’s jury run for King’s Health Partners, where members of the public explored how they would like facts on screening presented.

Why did you choose an animation in this case?

This was an online guide, and so lends itself well to multimedia components.  We decided to test out an animation because it allowed us to:

  • Break down the stats into ‘chunks’, so we could build up the story piece by piece
  • Show multiple icon arrays and highlight certain numbers
  • Include narration to further support people in understanding the facts

How did you design and test the animation?

We consulted with risk communication expert Professor David Spiegelhalter for the functionality and design of the animations. Professor Spiegelhalter is Winton Professor of the Public Understanding of Risk in the Statistical Laboratory, University of Cambridge.

As with the overall guide, we developed the animation script in house at Breakthrough Breast Cancer and it was reviewed by experts in the field. The animation was programmed in house using Adobe Flash. We included the animation in user testing of the website, to ensure people liked the format, understood the key statistics, and found it useful for supporting them in making an informed choice.

Top tips

Animations needn’t be expensive. In the YouTube era, people are used to viewing videos that are rough around the edges, so budgets need not be large. However, if you don’t have the in-house capability or budget to make an animation, there are still some general principles you can use:

  • Use absolute numbers to explain risk, not percentages alone
  • Keep your denominator the same when possible, and as low as you can
  • If you have room, use a simple icon array
  • Use words like ‘about’ and ‘roughly’ to communicate uncertainty about stats when needed
  • As with everything, test out your ideas with your audience

Find out more

We’re all very happy to hear from you!

  • For more about the charity’s health information: Eluned Hughes, Head of Public Health and Information, Breast Cancer Now,
  • For advice on risk communication and content development: Hannah Bridges, Health Content Specialist,
  • For technical advice on developing animations and videos: Chris Joseph, Digital Producer,

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