Evaluation of an indirect record linkage method in an examplary study on the risk of cancer and cancer mortality in type 2 diabetes patients treated with different antidiabetics


In this study, an exemplary study of cancer risk and cancer mortality in type 2 diabetes patients treated with different antidiabetic therapies serves to evaluate to which extent easier data access can be facilitated using different methods of linking pseudonymized claims data to data from epidemiological cancer registries in Germany.
First, an indirect record linkage will be performed using year of birth, sex, community code, and date/quarter of the tumor diagnosis. Second, the results will be evaluated by a well-established and exact, yet elaborate linkage procedure using so-called control numbers. As such a linkage requires a very stringent data protection concept and is very time-consuming, it is not feasible for every research question. Using the exemplary study, the differences in quality between the two linked datasets will be described and assessed. The overall objective of this project is to optimize the linkage procedures of both methods in order to give recommendations for the cost and time-efficient conduct of further studies with specific data protection requirements.

Funding period

Begin:   January 2017
End:   May 2021


  • German Research Foundation


Dr. rer. nat. Bianca Kollhorst


  • PD Dr. med. MSPH Wolfgang Rathmann (Deutsches Diabetes-Zentrum (DDZ))