Effects of a modified invitation letter to follow-up colonoscopy for bowel cancer detection

To investigate whether modifications made to the current National Health Service (NHS) invitation letter for follow-up colonoscopy examination affect participant state anxiety and behavioural intentions to attend.

Five hundred and thirty-eight adults of bowel cancer-eligible screening age (56-74) were randomized to receive the current NHS invitation letter or the modified version of the letter as a hypothetical scenario. Modifications to the letter included fewer uses of the term cancer and awareness of alternative screening options. The history of the colonoscopy invitation, anticipated state anxiety, behavioural intention to attend the nurse appointment, and colonoscopy concerns upon reading the letter were measured.

Behavioural intentions were high in both conditions; however, participants reading the current letter reported significantly higher behavioural intentions compared to the modified letter. There was no main effect of previous invite status or interaction between previous invite status and letter condition on behavioural intentions. However, the effect of the letter on levels of anxiety depended on the participant's invitation history. Those never invited for a colonoscopy were more anxious when reading the modified letter compared to the current letter. Conversely, previous colonoscopy invitees were less anxious following reading the modified letter than those reading the current letter. Those never invited for a colonoscopy were more concerned about embarrassment and test invasiveness. All findings remained the same when controlling for age and education.

Modifications to the invitation letter were not beneficial to levels of screening intention or anxiety.