Use and results of screening colonoscopy at 50 to 54 year old women and men

Interventions: Group 1: Circular of the respective health insurance companies at their 50-54 years old insured persons. Besides the information about the offer of screening colonoscopy from the age of 50 and the invitation to its awareness, the letter contains a one-minute risk self-check for colorectal cancer (intervention group). Group 2: Circular of the respective health insurance companies at their 50-54 years insured persons. The letter includes information about the offer of screening colonoscopy from the age of 50 and invitation to its awareness. The letter does not contain a one-minute risk self-check for colorectal cancer (control group). Primary outcome(s): Increase of colorectal neoplasm detection rates through an invitation letter containing a risk self-check compared to an invitation letter without risk self-check. Study Design: Allocation: Randomized controlled study; Masking: Blinded (masking used); Control: Other; Assignment: other; Study design purpose: prevention