Table 1. Colorectal cancer screening options in Germany before and during the study period.
| Period | Age | Test | Interval |
| 1977 to September 2002 | ≥ 45 | gFOBT | Annually |
| October 2002 to March 2017 *1 | 50–54 | gFOBT | Annually |
| ≥ 55 | Colonoscopy | Up to two colonoscopies ≥ 10 years apart*2 | |
| Alternatively: gFOBT | Biennially |
gFOBT, Guaiac-based fecal occult blood test
*1 Changes since March 2017:
- In April 2017 gFOBT was replaced by the immunological fecal immunochemical test (iFOBT).
- Since April 2019 colonoscopy is offered from age 50 years for men (unchanged for women).
- Since July 2019 personal invitation letters are sent to persons aged 50, 55, 60, and 65 years.
*2 Second screening colonoscopy offered only if first screening colonoscopy was done before age 65.