Telephone Services for Participation in Colorectal Cancer Screening

A multicentre randomized health services study within the population-based primary colonoscopy screening program (PCSP) in Poland. Individuals, aged 55-60 years, willl be randomized in a 1:1:1 ratio to arms: (1) Invitation by post, (2) Call Center or (2) Combined invitation methods. The primary outcome measure is rate of participation in screening colonoscopy. The sample size of 6 300 participants will detect 3 to 5 percentage point differences (depending on the arms comparison) in participation rate between groups with 80% power and significance level 0.05, using Ochran-Mantel-Haenszel test.