The impact of redesigned advance notification letters on intention to screen for bowel cancer: a randomised...

The aim of this study was to examine the impact of redesigned advance notification letters on screening intention and the moderating role of screening barriers/facilitators.

In an online survey, 562 Australians aged 50-74 years were randomised to view one of three letters: the current letter (control) or one of two redesigns with enhanced graphics and evidence-based messaging. Participants rated their screening intention before and after viewing, with screening barriers and facilitators also measured.

The redesigned letters did not increase screening intention over the control [control vs. Redesign 1: the estimated effect of the predictors (b)=0.12, p=0.204; control vs. Redesign 2: b=0.07, p=0.471]. Higher self-efficacy (b=0.12, p<0.001), perceived benefits (b=0.12, p<0.001), lower autonomy concerns (b=-0.23, p<0.001), avoidance (b=-0.16, p=0.004), disgust (b=-0.12, p=0.011) and perceived difficulty (b=-0.02, p<0.001) moderated the letters' effect on intention for all letter versions.

Advance notification letters increase intention, with certain reactions (e.g. high self-efficacy and perceived benefits) enhancing this effect. Design and content changes may not improve impact beyond the letter's intrinsic effect.

Multi-pronged approaches may better address individual barriers. Exploring digital formats may enhance advanced notification effects.