NordICC (The NordICC Initiative on Colorectal Cancer, NCT00883792) is a multicenter randomised trial to investigate the effect of screening colonoscopy on CRC incidence and mortality. In Poland, in Warsaw area, at least 10,000 subjects 55-64 years of age are to be invited to screening colonoscopy. A personal letter of invitation containing date and hour of appointment is mailed to every individual randomised to the screening group. Up to 60% of invitees do not respond to the initial invitation and reminding letter. The aim of this study is to compare the effect of reminding letter and educational intervention on attendance to screening colonoscopy in nonresponders to initial invitation to screening colonoscopy.
