Participation in Screening Colonoscopy in Response to an Advanced Notification Letter Plus Standard Invitation Versus Standard Invitation Only - a Population-based Randomized Controlled Trial

Participation in a primary screening colonoscopy programs remains low. Advanced notification letter has been shown to increase participation in colorectal cancer screening with fecal occult blood testing and to be cost effective compared to standard invitation. It is unknown whether advanced notification letter increases participation rate in primary colonoscopy screening program.

We hypothesize that an Advance Notification Letter will have significant influence on participation in screening colonoscopy, comparing to standard invitation procedure and will thus result in higher efficiency of the program.

This randomized controlled study aims to compare the participation rate in screening colonoscopy in response to advanced notification plus standard invitation letter and standard invitation letter alone.

Material and methods: 6800 individuals aged 55-64 years will be drawn from the Population Registry and randomly assigned in a 1:1 ratio to the group invited for screening colonoscopy with advanced notification letter (send two weeks before standard invitation) plus standard invitation (send six weeks before planned screening colonoscopy) or to standard invitation only (send six weeks before planned screening colonoscopy). The sample size was calculated to detect 3% difference in participation rate between the groups (25% vs 28%) with 80% power.