  Summarization of clinical narratives is a long-standing research problem.
Here, we introduce the task of hospital-course summarization. Given the
documentation authored throughout a patient's hospitalization, generate a
paragraph that tells the story of the patient admission. We construct an
English, text-to-text dataset of 109,000 hospitalizations (2M source notes) and
their corresponding summary proxy: the clinician-authored "Brief Hospital
Course" paragraph written as part of a discharge note. Exploratory analyses
reveal that the BHC paragraphs are highly abstractive with some long extracted
fragments; are concise yet comprehensive; differ in style and content
organization from the source notes; exhibit minimal lexical cohesion; and
represent silver-standard references. Our analysis identifies multiple
implications for modeling this complex, multi-document summarization task.
