Preparedness deserts: a framework for understanding and addressing geographic inequities in bystander response to out-of-hospital cardiac arrest.

Geographic disparities in out-of-hospital cardiac arrest (OHCA) survival are well-documented, with predominantly Black and low-income communities experiencing significantly worse outcomes than affluent White neighborhoods. These disparities persist independently of patient-level factors, implicating structural determinants that shape bystander response capacity. This commentary introduces the concept of preparedness deserts as an analytic framework for moving beyond documentation of disparities toward targeted intervention. The framework distinguishes between training access and equipment access as distinct but interrelated dimensions of preparedness infrastructure and emphasizes temporal accessibility as a critical but often overlooked component of automated external defibrillator (AED) coverage. Drawing on Chicago as an illustrative case, this paper operationalizes the preparedness desert concept, examines mechanisms perpetuating inequity across the earliest links in the chain of survival, and proposes actionable strategies for equitable resource allocation. Rather than attributing disparities to individual bystander behavior, the framework directs attention to modifiable structural conditions amenable to policy intervention.