gms | German Medical Science

66. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS), 12. Jahreskongress der Technologie- und Methodenplattform für die vernetzte medizinische Forschung e. V. (TMF)

26. - 30.09.2021, online

The technical principles of the ILEG study– preparing the connection of primary and secondary healthcare data

Meeting Abstract

  • Julia S. Volmerg - Medizinische Fakultät der RWTH Aachen, Aachen, Germany
  • Jonas Bienzeisler - Medizinische Fakultät der RWTH Aachen, Aachen, Germany
  • Andrea Klausen - Carl von Ossietzky Universität, Oldenburg, Germany; Medizinische Fakultät der RWTH Aachen, Aachen, Germany
  • Insa Seeger - Carl von Ossietzky Universität, Oldenburg, Germany
  • Ulf Günther - Klinikum Oldenburg, Oldenburg, Germany
  • Stefan Thate - Stadt Oldenburg - Feuerwehr, Oldenburg, Germany; Carl von Ossietzky Universität, Oldenburg, Germany
  • Wiebke Schirrmeister - Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany
  • Antje Timmer - Carl von Ossietzky Universität, Oldenburg, Germany
  • Rainer Röhrig - Medizinische Fakultät der RWTH Aachen, Aachen, Germany

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie. 66. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS), 12. Jahreskongress der Technologie- und Methodenplattform für die vernetzte medizinische Forschung e.V. (TMF). sine loco [digital], 26.-30.09.2021. Düsseldorf: German Medical Science GMS Publishing House; 2021. DocAbstr. 10

doi: 10.3205/21gmds034, urn:nbn:de:0183-21gmds0343

Published: September 24, 2021

© 2021 Volmerg et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Introduction: To counteract the exuberant usage of the emergency medical service (EMS) [1] and external reasons for crowding in an emergency department (ED) [2], the project Gemeindenotfallsanitäter (GNFS) was established. The GNFS is a trained paramedic equipped to treat a patient at home rather than calling an EMS or visiting an ED [3]. This concept has been proven useful in several projects worldwide [3], [4]. The ILEG study was conducted to evaluate the impact of introducing the GNFS for example on the frequencies of emergency calls, visits of an ED or ecological impact with a before-after comparison. The ILEG project requires a specialised infrastructure for data collection and processing in conformity with the EU-GDPR.

State of the Art: Usage of record linkage can have several approaches depending on the project. In studies covering only one clinic or hospital, the use of one unique ID is sufficient for record linkage and privacy. In complex studies, especially with follow ups in primary, secondary and tertiary care providers a trusted third party (TTP) is needed, to gather and link identifying data (IDAT) and manage different IDs and pseudonyms from different health care providers and several tools to support an id & consent management are established [5], [6], [7]. With higher number of collected data heuristic record linkage approaches [8] could be employed, but the study is only concepted for approx. a thousand datasets.

Concept: The presented study collects data from the GNFS-documentation, self-reports of patients, general practitioners, EMS, the EDs and from the local dispatch. To link the data of the participating institutions a TTP is established. IDAT is recorded with the MOSAIC-Framework [7] by GNFS, supported by study nurses. Unique codes are printed onto the informed consents, case report forms, and surveys to enable the record linkage of medical data (MDAT) form different sources. Data from the participating ED is collected with the AKTIN-Infrastructure [9].

Implementation: The TTP is responsible to verify the informed consent, and to retrieve the data from the different sources. To ensure a strict separation between identifiying and medical data, the latter is collected with a matching Software that encrypts it, but leaves the IDAT unencrypted. In the next step, the IDAT are pseudonymize with the MOSAIC-Framework [7], and the data is directed to the research centre.

Lessons Learned: The established infrastructure enables the TTP to link the IDAT and therefore MDAT from several institutions. The software allows to protect MDAT by encryption. During the first steps of the project, it was found to be necessary to additionally establish an ID printed onto documents, as it ensures a link between the documents provided by the GNFS, the dispatch and the study nurse, who sends and retrieves the surveys. This made unforeseen steps necessary to avoid needless knowledge of IDAT within the tools, i.e. additional restriction of access to the MOSAIC-Framework.

The authors declare that they have no competing interests.

The authors declare that a positive ethics committee vote has been obtained.


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