The effect of four interventions to improve cancer screening behaviour

Today, research investigating ways to increase the number of people taking part in the national bowel cancer screening programme in England is published in The Lancet.  This research was conducted by UCL, along with their collaborators at Imperial College London, Queen Mary University of London and each of the NHS Bowel Cancer Screening Hubs across England.

Bowel cancer (also known as colorectal cancer) remains one of the most commonly diagnosed cancers in the UK and is the second biggest cause of cancer deaths. The NHS in England manages a bowel cancer-screening programme which aims to find bowel cancer at an early stage when it can be treated more successfully. The screening programme invites men and women to complete a home-based test called a FOB (faecal occult blood) test every two years from age 60 to 74.

However, only about 1 in 2 people actually take part in the screening programme and data shows that the number of people doing the test is much lower (35%) among people who live in some of the poorest areas in England compared to those living in the richest areas where uptake is about 60% (von Wagner et al, 2011).

As everyone can benefit from having bowel cancer found early out team of researchers developed four separate interventions to try and reduce the difference in uptake between people in poor and rich areas. Each intervention was tested in a randomised controlled trial built into the Bowel Cancer Screening Programme and involved 747,856 people across the whole of England.

The interventions consisted of simple changes or additions to the material people already receive from the Bowel Cancer Screening Programme when they are first invited to take part:

1. Gist leaflet: An additional ‘gist’ leaflet was added to the usual information material sent out to invitees. This leaflet summarised the key points about bowel cancer screening using simple language and in an ordered format to help guide the reader through all the information needed to make a screening decision. The front page included bullet points of facts considered essential to making a screening decision e.g. how common bowel cancer is. The reader was then encouraged to turn the page for more information about the screening test e.g. how the test works and what happens after completing the test. For those wanting further, more detailed information, they were instructed to read the usual ‘Facts booklet’ sent with the leaflet (Smith et al, 2013; Smith et al, 2013, Smith et al, 2015).
2. Narrative leaflet: An additional ‘narrative’ leaflet was added to the usual information material sent out to invitees. This leaflet provided stories and quotes from people who had previously taken part in bowel cancer screening, selected to address known barriers (e.g. disgust at having to handle poo samples) and motivators (e.g. having peace of mind from a negative test result) to screening. Photos of those who provided their stories of screening were included to legitimise the quotes and help the reader connect with others who have overcome barriers and completed the screening test (McGregor et al, 2015).
3. General Practitioner (GP) Endorsement: The usual invitation letter included a section at the top highlighting that the individual’s GP practice supported bowel cancer screening. Wendy Atkin and her team at Imperial College London contacted all GP practices in England to ask them to help with this study and 80% agreed to have their support stated on the letters.
4. Enhanced Reminder: The usual reminder letter included a section at the top highlighting the statement ‘A reminder to you’ to try and get people’s attention. Towards the end of the letter a section was added to highlight key points to remember when thinking about whether to take part in screening or not: a) that a person’s risk of getting bowel cancer increases as they get older, b) that finding bowel cancer early can make successful treatment more likely, and c) that it is not too late to do the test.

The results found that the GP Endorsement and the Enhanced Reminder increased overall uptake of bowel cancer screening, but the effect was very small. Importantly, only the Enhanced Reminder managed to narrow the gap between those living in rich and poor areas.

Unfortunately, despite being found to increase knowledge about bowel cancer and screening (Gist leaflet), and intentions to have screening (Narrative leaflet) in earlier, smaller studies, both leaflets failed to make a positive impact on the number of people who actually take part in bowel cancer screening.

These results show just how difficult it is to change health related behaviours and the continuing challenge faced by public health researchers. It would appear that more profound changes to the current bowel cancer screening programme are needed to substantially reduce the gap between people living in rich and poor areas.

In the meantime, even a small increase in uptake can have a huge impact on the national burden of bowel cancer. The GP Endorsement and the Enhanced Reminder are simple, low-cost interventions that could easily and quickly be integrated into the current programme and, therefore, should perhaps be considered for adoption by the NHS.

This research was funded by the National Institute for Health Research and the results are now published in The Lancet.

Wardle, von Wagner et al (2015). Effects of evidence-based strategies to reduce the socioeconomic gradient of uptake in the English NHS Bowel Cancer Screening Programme (ASCEND): four cluster-randomised controlled trials. The Lancet, Published Online:08 December 2015.