DOI: 10.1136/bmjopen-2025-111175 ISSN: 2044-6055

Development of phenotype algorithms for the detection of adverse events in electronic health record data: a multicentre study

Louisa Redeker, Annette Haerdtlein, Anna Maria Wermund, Beate Mussawy, Marietta Rottenkolber, Martin Coenen, Pauline Dürr, Martin Federbusch, Christian Philipp Jüttner, Anna Kathrin Schuster, Hanna Marita Seidling, Alexandr Uciteli, Christoph Beger, Daniel Neumann, Markus Loeffler, Tobias Dreischulte, Sven Schmiedl

Objectives

To develop phenotype algorithms for the detection of adverse events (AEs) or AE-proxies in electronic health records (EHRs), accounting for varying data availability.

Design

Multicentre study conducted as part of the Use Case POLAR_MI (POLypharmacy, drug interActions, Risks) of the German Medical Informatics Initiative (MII).

Setting

Germany.

Participants

Multidisciplinary teams from 10 German university sites within the MII.

Interventions

Not applicable.

Main outcome measures

Literature- and consensus-based development and operationalisation of AE algorithms using structured EHR data, including a standardised, multicentre expert review process. Data categories used: International Classification of Diseases, 10th Revision (ICD-10) codes for diagnoses; Anatomical Therapeutic Chemical (ATC) codes and ‘Pharmazentralnummern’ (PZN; German eight-digit identification code for pharmaceutical products) for medications (used in the treatment of AEs); Logical Observation Identifiers Names and Codes (LOINC) for laboratory values and medical findings; and ‘Operationen- und Prozedurenschlüssel’ (OPS; German procedure classification) codes for medical and surgical procedures.

Results

We developed 82 algorithms for 48 AEs. Algorithms for the same AE varied by data categories or code selections. At the AE level, 31 AEs were covered exclusively by newly developed algorithms, and 17 AEs by at least one modified algorithm.

Overall, 52 algorithms were based on a single data category, while 30 required multiple categories. ICD-10 codes were most commonly used (n=65 AE algorithms), followed by LOINC (n=27), ATC codes (n=18), OPS codes (n=11) and PZN (n=2). All phenotype algorithms were semantically modelled and can be executed using the publicly available Terminology- and Ontology-based Phenotyping (TOP) Framework, which supports export in various formats.

Conclusion

We present a peer-reviewed set of algorithms for a large number of AEs, which can be implemented in structured routine electronic data sources and (pending validation studies) may support pharmacoepidemiologic research. The algorithms will be implementable across all 39 participating sites of the German MII. As a next step, we will empirically validate the algorithms against all information (including free text) contained in EHRs.

Trial registration

Not applicable.

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