The Generativity of Variability for Evidence-Based Practice.

The evidence-based practice (EBP) paradigm has become a dominant approach to clinical care, organizing healthcare around the production, synthesis, and implementation of evidence. Yet despite sustained efforts to standardize practice in terms of evidence, variability in care delivery, outcomes, and decision-making persists. Nursing scholarship has critically examined EBP as a dominant epistemological orientation to practice, often identifying variability as that which troubles the evidentiary aspiration to standardize, generalize, and govern practice. Building on this work, I take variability as a starting point for examining how healthcare is configured as an evidentiary domain in the first place. Drawing on Michel Callon's concepts of framing and overflowing, EBP is approached as an ongoing effort to make clinical practice sufficiently calculable, comparable, and actionable. The analysis shows how variability appears not simply as what exceeds or opposes evidence, but as that which is directly operative in the processes through which evidentiary arrangements are developed, enacted, and transformed. In this way, evidence and practice emerge not as pre-existing domains requiring reconciliation, but as ongoing accomplishments produced through processes of framing and overflowing. What then becomes visible is the continual formation of healthcare, where evidentiary arrangements, clinical practices, problems, and possibilities are continually encountered, enacted, and made consequential, inviting inquiry into the ways nursing participates in these processes.