Toward Understanding Clinical Context of Medication Change Events in Clinical Narratives

Understanding medication events in clinical narratives is essential to achieving a complete picture of a patient's medication history. While prior research has explored identification of medication changes in clinical notes, due to the longitudinal and narrative nature of clinical documentation, extraction of medication change alone without the necessary clinical context is insufficient for use in real-world applications, such as medication timeline generation and medication reconciliation. In this paper, we present the Contextualized Medication Event Dataset (CMED), a dataset for capturing relevant context of medication changes documented in clinical notes, which was developed using a novel conceptual framework that organizes context for clinical events into various orthogonal dimensions. In this process, we define specific contextual aspects pertinent to medication change events (i.e. Action, Negation, Temporality, Certainty, and Actor), describe the annotation process and challenges encountered, and report the results of preliminary experiments. The resulting dataset, CMED, consists of 9,013 medication mentions annotated over 500 clinical notes. To encourage development of methods for improved understanding of medications in clinical narratives, CMED will be released to the community as a shared task in 2021.