Evaluation of breast cancer mortality in the German Mammography Screening Program - Main Phase 1


Evaluation of Breast Cancer Mortality in the German Mammography Screening Program
(Main Phase I)
Since 2009, the Mammography Screening Program has been introduced nationwide in Germany. Only after its introduction were various ways of evaluating the program’s effectiveness in reducing breast cancer mortality investigated. The so called “ZEBRA-HS-I” project is such an evaluation and was mandated by law.
As part of the ZEBRA-HS-I project BIPS carries out a cohort study based on so-called secondary data (i.e., the data was collected in a different context and this project uses it in a 'secondary' way). BIPS maintains a nationwide sample of pseudonymized claims data from statutory health insurance providers (SHIs), which will play a key role in the project. In the already completed feasibility phase of this project (see projects Mach I and Mach II), our institute was able to demonstrate that these data are suitable for the planned analyses.
The aim of the currently running first phase of the main study of the project (ZEBRA-HS-I) is to develop the data basis and the methodology for the analyses planned in the second phase of the main study, which aims to compare breast cancer mortality in participants and non-participants of the Mammography Screening Program. Since the considered endpoint of this study (breast cancer mortality) is a relatively rare event, a very large study population is required for a precise estimation of a possible effect of the screening program. Furthermore, an effect of the program could only be measured at population level approx. 6–10 years after screening participation, which requires a long follow-up of the study population. A particular challenge for the analyses is the fact that women who take part in the screening probably differ from non-participants in terms of risk factors, among other things. The resulting selection bias must be taken into account in the statistical analyses.
In the current project phase ZEBRA-HS-I, BIPS is primarily working on the following tasks:
• Developing the data basis for the planned analyses, which will comprise 15 data years and approx. 15% of the women eligible for participation in the screening program
• Supplementing SHI data with information on the cause of death of deceased insured persons
• Implementing procedures to control for selection bias in preparation of the planned analyses
The data basis will comprise pseudonymized data from five SHIs for the years 2004–2018. The missing information on the cause of death in SHI data will be supplemented on the one hand by matching with data from cancer registries and on the other hand by applying an algorithm based on SHI data. To control for selection bias in the statistical analyses, innovative procedures will be developed taking into account the special setting of the German Mammography Screening Program.

Funding period

Begin:   January 2018
End:   March 2021


  • Federal Office for Radiation Protection


Dr. rer. nat. Ingo Langner

Project management (national)

Dr. Heike Wersching, Universität Münster, Deutschland


  • Dr. Joachim Kieschke (Epidemiologisches Krebsregister Niedersachsen)
  • Dr. Monika Klinkhammer-Schalke (Arbeitsgemeinschaft Deutscher Tumorzentren)
  • Dr. Martin Meyer (Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit)
  • Dr. Heike Minnerup (Institut für Epidemiologie und Sozialmedizin, Westfälische Wilhelms-Universität Münster)
  • Prof. Heinz Rothgang (SOCIUM Forschungszentrum Ungleichheit und Sozialpolitik, Universität Bremen)
  • Dr. Andreas Schützendübel (Landeskrebsregister Nordrhein Westfalen)