Increasing Uptake of Bowel Screening

Bowel cancer is the second biggest cancer killer in the UK, accounting for over 16,000 deaths per year. Screening can reduce deaths from bowel cancer if the people invited participate. The challenge is that high uptake of bowel screening is hard to achieve, and remains persistently below 65%. The faecal immunochemical test (FIT) is the most widely used bowel screening test worldwide. In the UK, FIT kits are mailed to people's homes without guidance on when the kit should be returned and only brief instruction on how to use it. Some people have said that even though they intend to complete and return the kit, they often forget or put off doing it. Two approaches are proposed to addressing this issue: i) providing a suggested deadline for FIT return, because it is known from breast and cervical cancer screening that giving people an appointment time increases uptake compared to an open invitation, and ii) planning sheets, that have been found to help people act on their intentions in other health contexts. This trial aims to evaluate the impact of providing a suggested deadline and a planning sheet on the return of FIT bowel screening kits. The trial is integrated within the Scottish Bowel Screening Programme. The investigators will randomly allocate 40,000 consecutive people that are due to be sent a FIT kit to one of eight groups: (i) control group (no deadline, no planning sheet), (ii) intervention group (1-week deadline, no planning sheet), (iii) intervention group (2-week deadline, no planning sheet), (iv) intervention group (4-week deadline, no planning sheet), (v) intervention group (no deadline, with planning sheet), (vi) intervention group (1-week deadline, with planning sheet), (vii) intervention group (2-week deadline, with planning sheet), (viii) intervention group (4-week deadline, with planning sheet). It will then be examined if having a suggested deadline and a planning sheet affects how many people send back their completed FIT kit. It will als