Encouraging compliance with bowel and cervical cancer screening using behavioural nudges

INTERVENTION: All participants will have either not attended a cervical cancer screening appointment, or not sent a bowel screening test back in the previous 12 months. Participants will be randomly allocated to one of three groups: the control arm which will receive no additional intervention, a letter‐only arm who will receive a behavioural science informed letter and a lottery arm who will receive the same basic letter and be entered into a regret lottery. Randomisation will be individual and will be a simple randomisation. Randomisation will be conducted by GP practices. For all arms, we will monitor whether they book and attend an appointment (cervical cancer screening patients) or send back the screening kit (bowel cancer screening patients) 12 weeks after the letter is sent out (both arms receiving letters will be sent on the same day). There will be no follow‐up. GP practices are responsible for informing the investigators which people send their bowel cancer screening kits back, and which individuals attend a cervical cancer screening. Participants will be blind to the condition they are in, though GP practices will maintain a record of who is in what arm as they will be sending the letters to households. CONDITION: Compliance with mass cancer screening programmes ; Not Applicable ; Compliance with mass cancer screening programmes PRIMARY OUTCOME: ; 1. Attendance at cervical cancer screening appointments within 12 weeks of the letter being sent for the cervical cancer group, measured using the date of booking and attending the appointment and reported by GP practices (if any); 2. Ordering and sending back a bowel cancer screening kit within 12 weeks of the letter being sent for the bowel cancer group and reported by GP practices (measured using the date of sending back the kit (if any); INCLUSION CRITERIA: 1. Eligible and sent a letter for but not attended a cervical cancer screening appointment OR not sent a bowel cancer screening test back in the previous twelve months. 2. Aged 18 years or older 3. Attending North Lincolnshire practices