A randomized controlled trial testing behavioral economics messages and screening choices to increase participation...

Behavioural economics (BE)-inspired messages within invitations for immunochemical faecal tests (FIT), or offering alternative tests such as sigmoidoscopy (FS) or CT-colonography (CTC), are strategies to re-engage non-respondents in subsequent colorectal cancer (CRC) screening rounds. This study evaluated their impact on screening participation.

In 2022-2023, a randomized controlled trial was conducted involving 20,225 non-respondents to the CRC Florence screening program. Individuals aged 54-70 were randomized into six groups: a control group receiving the standard invitation letter (SL); three groups receiving SL plus a feedback message (F), a social norm message (MN), or both (F+MN); and two groups offered FS or CTC as alternatives to FIT among invitees aged 58-60. The primary outcome was participation within 90 days. The trial was registered with ISRCTN (ISRCTN11841256).

Participation was 5.7% in controls, and 7.4%, 6.7%, 6.6%, 2.0%, and 4.1% in the F, MN, F+MN, FS, and CTC groups. Invitees in the F group were more likely to participate (aOR=1.32; 95%CI:1.10-1.57), while FS invitees were less likely (aOR=0.39; 95%CI:0.27-0.54). CTC participation resembled controls aged 58-60 and was twice that of FS.

BE-inspired interventions can increase CRC screening participation, whereas more invasive alternative tests did not. Future studies should explore preferences for different screening tests to identify more acceptable modalities and optimise participation.