Assessing medical radiation exposure in the German National Cohort


Radiation exposure in the general population is essentially determined by two sources: medical exposure and exposure from natural sources. However, the exact extent of exposure and associated doses is not known due to a lack of population-based data. Ionizing radiation (IR) is a carcinogen; in addition, IR also increases the risk of a number of non-cancer diseases. Assessing radiation exposure in participants is therefore, on the one hand, relevant for quantifying IR-associated risks, in particular with regard to medical-diagnostic exposures, and on the other hand as a confounder for other risk-relationships. In addition, assessing radiation exposure of participants has not yet been done in any of the ongoing large population-based cohorts (UK biobank and others). The Federal Commission on Radiological Protection explicitly supports the inclusion of radiation exposure in the National Cohort. There is also a need for further research on the assessment of radiation exposure from computed tomography (CT) and other examination modalities involving substantial radiation doses.

The feasibility of assessing medical radiation exposure using a questionnaire approach was examined in a feasibility study in 200 participants from November 2010 to October 2012 (Dreger et al., 2015). It was found that a retrospective assessment of diagnostic-medical exposures over a period of a few years, especially with regard to CT examinations, is possible using a questionnaire. Linkage with secondary data from health insurance claims was done and showed be particularly advantageous for the prospective assessment of diagnostic exposures. It was noticeable that nearly every second individual reported to have already had a CT scan with comparatively high doses.

In the present study, study participants are expected to complete a questionnaire that has already been used in the feasibility study but will be significantly shortened, with a specific focus on CT and other examinations with relatively high radiation doses. This is supplemented with questions on the medical indication of the reported examinations (i.e., fractures, traffic accidents, etc.). The survey is to be carried out independently via touchscreen. Two questionnaires or internet questionnaires are to be used at two time points during the project period in order to assess new exposures with ionizing radiation. X-ray passes are distributed, in which certain parameters that are important for dose estimation, e.g. dose area product, and to be entered by the radiological practices or clinics/hospitals. Therapeutic exposures are not the main focus of this assessment and are addressed only with a few questions.

Overall, it is aimed to recruit 3,000 participants in four study centers: Bremen, Essen, Neubrandenburg / Neustrelitz, and Augsburg (about 750 individuals each, consecutively recruited).

Funding period

Begin:   May 2017
End:   September 2019


  • Federal Office for Radiation Protection


 Steffen Dreger


  • Prof. Dr. Jöckel Karl-Heinz (Institut für Medizinische Informatik, Biometrie und Epidemiologie (IMIBE), Universität Essen-Duisburg)
  • Dipl.-Phys. Jürgen Kopp (Stabstelle Med. Physik/Strahlenschutz, Klinikum Augsburg)
  • Prof. Dr. Jakob Linseisen (Abteilung Epidemiologie II, Helmholtz-Zentrum München)
  • Prof. Dr. Christine Meisinger (Abteilung Epidemiologie II, Helmholtz-Zentrum München)
  • Dr. Börge Schmidt (Institut für Medizinische Informatik, Biometrie und Epidemiologie (IMIBE), Universität Essen-Duisburg)
  • Prof. Dr. Henry Völzke (Institut für Community Medicine, Universitätsmedizin Greifswald)