Antimicrobial Resistance (AMR) development map: narrative overview and a conceptual map to aid economic evaluation of AMR interventions

Introduction: Antimicrobial resistance (AMR) is a complex, inter-sectoral and international problem. Economic evaluation (EE) methods offer systematic, evidence-driven approaches to inform policy decisions about which AMR interventions to fund. EE of AMR interventions is complicated due to diffuse effects, complex mechanics of the problem and high levels of uncertainty. The current AMR EE literature restricts the analytical scope, potentially resulting in omissions of effects that may limit the utility of EE to inform policy decisions. We aimed to systemise the key evolutionary and ecological processes of AMR to elucidate the paths through which AMR interventions impact population health and healthcare costs to support EE design and to support decision makers in understanding the limitations of EE evidence for decision-making. Methods: This is a narrative overview and a conceptual map that was developed based on literature review in consultation with experts across the relevant disciplines of molecular biology, infectious disease modelling, health economics and ecology. Results: The AMR development map: (1) distils the key AMR processes and process drivers behind AMR development; (2) maps the available types of AMR interventions to AMR process drivers; (3) proposes a way to conceptualise the spatial scope of analysis through considering the connectivity of the wider ecosystem; and (4) outlines the key dimensions that AMR burden and intervention effects could be measured across depending on the type of intervention and setting. A tool was developed to consider the AMR development map in conceptual modelling, with the focus on the choice of scope in the EE of AMR interventions. Discussion: This work summarises the key underlying biological principles of AMR development to provide mechanistical grounding for considering potentially relevant effects across the key dimensions and therefore aid conceptual modelling in EE of AMR interventions. This map can also facilitate identification of effects that cannot be considered or quantified, thus enabling transparency about these omissions within decision-making.