One Health antimicrobial resistance modelling: from science to policy

This paper reports on an international workshop examining how antimicrobial resistance (AMR) can be modelled across human, animal, and environmental sectors within a One Health framework. Effective AMR policy requires predictive models that anticipate the impact of interventions, yet major challenges persist, including uneven data quality, limited understanding of the relationship between antimicrobial use (AMU) and resistance, and the heterogeneity of AMR across species, genes, and settings. Variations between clinical and veterinary contexts, terrestrial and aquatic environments, and individual versus population-level dynamics complicate model generalisability. Despite this complexity, policymakers require simplified, synoptic AMR metrics to guide decisions. The paper reviews the current state of AMR modelling within a hierarchy of evidence for decision-making and draws lessons from modelling other complex environmental challenges to propose a more pragmatic, policy-oriented modelling approach.