News • Behavioural intervention study

Want to boost bowel cancer screening response? Add a deadline

Researchers found that adding a deadline to bowel screening invitation letters boosted test returns, with the largest effect for a 2-week return deadline.

The study, which was led by Professor Katie Robb from the University of Glasgow’s School of Health and Wellbeing, involved 40,000 adults in the nationwide Scottish Bowel Screening Programme. The findings were published in The Lancet.

Screening by self-sampled faecal immunochemical testing (FIT) reduces colorectal cancer mortality. However, a major challenge for colorectal screening worldwide is achieving high uptake. In Scotland, colorectal screening is offered to people aged 50-74, every two years, with participants mailed a single-sample FIT. The study team found that adding a single sentence suggesting a deadline for FIT return in the invitation letter to FIT colorectal screening boosted FIT return. The largest effect (2% absolute increase in FIT return) was seen with a 2-week deadline.

It is estimated that a 2% increase in FIT return would mean an additional 39,000 people participating in a two-year Scottish Bowel Screening round, with approximately 23 colorectal cancer deaths being avoided as a result. In addition, by increasing uptake in response to the initial invitation letter, fewer reminder letters will need to be sent to non-responders at six-weeks, and the burden on primary care and public health efforts outside the screening programme to increase uptake will also be reduced, further reducing costs.

Our findings demonstrate the potential for low- or no-cost behavioural interventions to boost participation in screening and reduce deaths from colorectal cancer
Katie Robb

The study also tested whether including a problem-solving planning tool in the colorectal screening invitation envelope increased FIT return. A list of possible concerns about completing the FIT along with tips to help participants overcome these concerns was provided, however, the tool had no positive impact on FIT return.

The Scottish Bowel Screening Centre sends FITs to approximately 1.95 million individuals every two years. Current uptake is 66%, therefore a third of the eligible population are not participating.

Katie Robb, Professor of Behavioural Science and Health in the School of Health and Wellbeing said: “Our findings demonstrate the potential for low- or no-cost behavioural interventions to boost participation in screening and reduce deaths from colorectal cancer. This is a considerable impact for an intervention which involves only adding one sentence to the invitation letter, which can be easily implemented into routine practice.”

Maxine Lenza, Cancer Research UK, Health Information Manager, said: "It’s great to see more research focused on improving the bowel cancer screening programme in a cost-effective way. Further research is now needed in larger and more diverse groups to better understand how effective a deadline is and what other simple methods can be introduced to break down barriers to taking part in screening. It’s important to read the information that comes with your invitation to decide if you’d like to take part. Bowel cancer screening aims to find cancer early or to prevent it developing. Cancer Research UK encourage people to take up bowel cancer screening when they’re invited.”

Scottish Government Minister for Public Health, Jenni Minto, said: “I thank the University of Glasgow for this vital research which highlights how a slight change in language has had a positive impact on bowel screening uptake. Although latest figures show screening uptake is exceeding the Healthcare Improvement Scotland standard of 60% in all Scottish Health Boards, more can be done to help detect cancer early. As most cancers that are diagnosed following a positive screening result are at the earliest two stages, when treatment is most likely to be successful, this is such a simple improvement.”

Source: University of Glasgow

17.03.2025