Inviting insurees to participate in screening for colorectal cancer

Interventions: Group 1: letter version 1, brochure version 1;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Group 2: letter version 1, brochure version 2;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Group 3: letter version 1, brochure version 3;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Group 4: letter version 2, brochure version 1;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Group 5: letter version 2, brochure version 2;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Group 6: letter version 2, brochure version 3;
The study consists of two parts: in part one (during the first year) participants receive conventional medical consulting. In the second part (years two and three) only physiscians
with a special training can participate in the study.
Primary outcome(s): informed decion in terms of participating in colorectal cancer screening (standardized questionnaire, Steckelberg et al.), assessed 3 months after distribution of screening information
Study Design: Allocation: Non-randomized controlled study; Masking: Open (masking not used); Control: active; Assignment: other; Study design purpose: screening