Abstract
This article contributes to the sociology of diagnosis by exploring how an acute medical condition, sepsis, was categorised over a 25-year period. We focus on publications reporting the outcomes of three consensus conferences that were convened to stabilise definitions of sepsis and on the failure of a controversial drug. We also focus on the category of severe sepsis by exploring why it was considered useful when introduced in 1991 but redundant by 2016. Drawing on insights from the sociology of valuation, our analysis of pivotal events within this period involving actors from clinical practice, biomedical science, regulation and industry identifies numerous and often contesting evaluative frameworks that came to bear on the categorisation of sepsis. Our analysis further reveals that the evaluative framework of clinical practice, mobilised by the professional specialty of intensive and critical care, became dominant in this categorisation, and that this did not reflect a dominance of biomedicine despite concerning an acute medical condition. Our contributions are to posit the ontological purpose of diagnostic categories and the role of valuation practices and strategic agency in diagnosis-as-category.