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

Abstract

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.

Introduction

Survival from out-of-hospital cardiac arrest (OHCA) varies dramatically across urban neighborhoods. In U.S. cities, survival rates in predominantly White, affluent areas can be two to three times higher than in predominantly Black or low-income communities.1, 2, 3, 4 This variation cannot be fully explained by differences in patient characteristics or cardiac arrest etiology; neighborhood-level factors contribute independently to outcomes.2, 3, 5 Addressing these structural determinants is essential to improving equity across the chain of survival.

Emergency response activation, high-quality cardiopulmonary resuscitation (CPR), and defibrillation are particularly susceptible to geographic inequities. Bystander CPR doubles survival odds,⁶ and timely defibrillation via public access AEDs can yield survival rates exceeding 50%.⁷ Yet national data consistently demonstrate that Black and Hispanic patients are less likely to receive bystander CPR,8, 9, 10, 11 communities with lower median incomes have fewer accessible AEDs,¹² and CPR training opportunities cluster in affluent areas.¹³ Although these disparities are well documented, less attention has focused on frameworks that translate documentation into targeted action. This commentary introduces preparedness deserts as an analytic framework for identifying gaps between emergency burden and response capacity and directing intervention.

The preparedness desert framework

The term “trauma desert,” introduced by Crandall et al., describes geographic areas distant from trauma centers where transport time contributes to mortality.¹⁴ Our “preparedness desert” concept extends this spatial framework to community-level response capacity: the infrastructure that determines whether bystanders can act effectively before institutional care becomes relevant.

We define a preparedness desert as a geographic area where response infrastructure is insufficient relative to community need. While high OHCA incidence increases urgency, communities with average incidence may warrant intervention if preparedness infrastructure is limited. This infrastructure comprises two dimensions: training access (availability of CPR/AED education shaped by proximity, cost, language, and reinforcement opportunities13, 15, 16 and equipment access (functional availability of AEDs, including spatial and temporal accessibility.12, 17 The distinction between spatial and temporal accessibility is critical. An AED 100 m from a cardiac arrest offers no benefit if locked inside a closed building; such phantom infrastructure inflates apparent coverage while providing no functional access during the hours when many arrests occur.¹⁷

The preparedness desert framework offers advantages over approaches that simply document outcome disparities. It provides an actionable diagnostic tool identifying modifiable deficits for intervention. Preparedness deserts vary in their composition: some communities have adequate equipment but limited training access, suggesting educational outreach as the priority; others have trained residents but lack accessible devices, indicating equipment placement as the more urgent need; still others face deficits across both dimensions, requiring comprehensive investment. By characterizing the specific nature of each community's preparedness gap, the framework enables targeted rather than one-size-fits-all interventions.¹³

This conceptualization aligns with fundamental cause theory: socioeconomic status produces health disparities through differential access to flexible resources such as knowledge, money, and social connections, which intertwine to protect health across multiple mechanisms.¹⁸ Public AEDs exemplify this dynamic: the intervention exists, but benefits accrue primarily to those with the socioeconomic capital to ensure devices are present in their environments and training is accessible to potential responders.9, 10 Preparedness infrastructure, like other health-protective resources, follows existing gradients of advantage unless deliberately redistributed.

While prior research has mapped neighborhood disparities in OHCA survival and optimized AED placement using geospatial modeling,¹⁹ these approaches typically examine isolated components of preparedness. The preparedness desert framework advances this literature by conceptualizing preparedness infrastructure as a multidimensional system integrating training access, equipment access, and temporal accessibility, linking these dimensions to structural patterns of resource allocation. Rather than documenting disparities alone, the framework offers a typology of preparedness deficits linking neighborhood-level issues to targeted intervention strategies.

Operationalizing the framework: Chicago as a case study

Chicago illustrates how preparedness deserts manifest in large metropolitan areas. Recent data demonstrates that OHCA survival in predominantly White community areas is approximately three times higher than in predominantly Black areas, a disparity persisting after adjustment for confounders.³ Bystander CPR rates exhibit corresponding geographic variation, with rates in South and West Side communities substantially lower than North Side neighborhoods.3, 20

Notably, Del Rios et al. found that while bystander CPR improved survival in predominantly White areas, this benefit was attenuated in predominantly Black neighborhoods.³ This finding, while potentially discouraging, is consistent with the preparedness desert framework: when AEDs are scarce and EMS response times prolonged, even high-quality CPR cannot compensate for deficits across other links.

Chicago's AED registry reveals device density concentrated in commercial and tourist areas rather than communities with the highest OHCA incidence.²¹ South and West Side neighborhoods have fewer registered devices per capita despite elevated cardiac arrest rates.3, 21

Beyond spatial distribution, temporal accessibility further constrains effective coverage. Research from other urban contexts indicates that accounting for building operating hours reduces effective AED coverage by more than 20%.¹⁷ Many Chicago AEDs are located in schools, government buildings, and health centers, which remain closed during evenings and weekends: hours when substantial proportions of cardiac arrests occur.²¹ This temporal mismatch creates illusory coverage.

Mechanisms perpetuating preparedness deserts

Multiple mechanisms perpetuate preparedness deserts, each suggesting targets for intervention. Financial barriers pose obstacles: CPR certification typically costs $50–100 through commercial providers, with additional indirect costs for transportation and time away from work.13, 15 This market-driven model commodifies survival knowledge, creating access gradients that parallel existing economic inequality. Geographic barriers compound financial ones, as training sites cluster in affluent areas where demand (and ability to pay) is concentrated, requiring residents of under-resourced communities to travel substantial distances for certification.¹³

Even when training is geographically accessible, linguistic and cultural barriers limit program reach. Standard curricula assume English fluency and familiarity with medical concepts, constraining accessibility for non-English speakers, while culturally adapted programming addressing community-specific concerns, such as fears about liability or causing harm, remains insufficient.16, 22 Psychological barriers further mediate whether training translates into action: fear of incorrect performance, uncertainty about when to intervene, and lack of confidence deter response even among trained individuals.13, 23 These barriers may be amplified by institutional mistrust and skill decay, suggesting one-time training is insufficient for sustained readiness.²⁴

Underlying these individual-level barriers are broader infrastructure allocation patterns. Decisions about where to place AEDs and offer training are made by institutions (employers, schools, municipalities, etc.) whose priorities and ability to purchase may not always align with epidemiological need.1, 12 These intersectional mechanisms interact: a resident of an under-resourced community faces not one barrier but a constellation of them, each reinforcing the others and collectively producing the preparedness deserts that shape survival geography.

From framework to action: operational pathway

The preparedness desert framework is not solely descriptive; it provides a structured pathway from identification to intervention. Operationalization involves four steps. First, map neighborhood-level OHCA incidence and survival and overlay preparedness indicators, including CPR training density, AED distribution, and temporal accessibility. Second, classify communities by deficit composition (training-limited, equipment-limited/temporally inaccessible, or compound). Third, deploy interventions aligned with the identified gap. Fourth, evaluate longitudinal changes in bystander response and survival.

This approach differs from undifferentiated expansion efforts by linking diagnosis to strategy.²⁵ A community with low training penetration but adequate AED coverage requires a different response than one with devices concentrated in locked buildings or absent entirely. By specifying the type of deficit, the framework directs targeted resource allocation rather than generalized calls for “more training” or “more AEDs.”

Applying the preparedness desert framework: targeted interventions

The preparedness desert framework requires differentiated intervention strategies tailored to a community's specific deficit type (Fig. 1). The following sections illustrate targeted operational strategies, organized by deficit category.

Fig. 1.

The preparedness desert typology: aligning community deficits with targeted interventions.

This matrix operationalizes the preparedness desert framework by distinguishing between training and equipment access, directing policymakers toward targeted, mechanism-specific interventions rather than generalized resource expansion.

Training access interventions

• 1.De-commodification: Treating CPR training as a public good rather than a market commodity removes financial barriers. Free, community-based training programs can reach populations excluded by cost barriers.22, 26, 27 Rigorous evaluation of such programs is needed, but the model demonstrates feasibility. Alternative low-cost approaches, including video-based self-instruction, have shown effectiveness in improving CPR skills among populations with limited access to traditional courses.²⁸
• 2.Trusted messenger delivery: Training delivered through institutions with existing relational capital, faith-based organizations, and community centers may overcome skepticism toward hospital-sponsored programs and address psychological barriers.²⁹ This approach is particularly important in communities where historical mistreatment has generated warranted mistrust of medical institutions.30, 31, 32
• 3.Embedded training: Integrating CPR education into existing touchpoints reduces geographic barriers and reaches populations unlikely to seek standalone certification. School-based CPR mandates, now enacted in most U.S. states, represent one such embedded approach; evidence suggests that training students creates multiplicative effects as knowledge transfers to family members and persists into adulthood.33, 34

Equipment access interventions

• 1.Equity-informed placement: In many U.S. jurisdictions, AED placement is driven primarily by private purchase, regulatory requirements, or institutional initiative rather than coordinated epidemiological optimization. Therefore, device distribution may reflect commercial density and organizational capacity more than neighborhood-level OHCA burden. Strategic frameworks should prioritize communities with the highest OHCA incidence and lowest functional coverage.³⁵ Overlaying placement decisions with social vulnerability metrics would help target areas where the gap between emergency burden and response capacity is greatest. Voluntary uptake alone is unlikely to correct geographic imbalances; equity-oriented redistribution may require policy mechanisms such as municipal subsidies, targeted public placement, public–private matching funds, or siting incentives tied to licensure.12, 36, 37
• 2.Temporal accessibility: Policies should encourage or require that publicly funded AEDs be placed in locations accessible 24/7 rather than buildings with limited operating hours.12, 17 At a minimum, device registries should incorporate temporal availability to enable accurate coverage assessment.
• 3.System integration: AED deployment must be paired with public awareness, signage, and dispatch integration.³⁸ Programs that link device registries with trained responder networks and mobile alert systems have demonstrated improvements in response time.³⁹ Devices that are unknown or difficult to locate offer limited benefit.

Policy infrastructure

Sustainable preparedness equity requires policy infrastructure rather than reliance on volunteerism, philanthropy, and sporadic grant funding. Municipal health equity plans could incorporate emergency preparedness as a standard domain with targets and accountability mechanisms. Inter-agency coordination between public health, emergency management, education, and EMS is essential for comprehensive approaches.

Metrics should move beyond counts of devices placed or people trained toward indicators capturing meaningful access: training rates in high-incidence areas, proportion of AEDs accessible 24/7, and bystander CPR rates in preparedness desert communities.

International experience demonstrates the feasibility of system-level preparedness reform. Denmark’s national AED registry and optimization strategies have improved functional accessibility, while Sweden’s mobile-phone lay responder dispatch system has demonstrated survival benefits through structured integration of community responders into EMS systems.12, 39, 40 These examples underscore that preparedness infrastructure can be intentionally engineered.

Limitations and future directions

The preparedness desert framework warrants empirical validation. Demonstrating that proposed indicators predict survival outcomes and that targeted intervention improves those outcomes remains essential. Comprehensive neighborhood-level data on training rates, AED accessibility, and bystander confidence are lacking in many cities, limiting the ability to fully characterize preparedness deserts. The framework focuses on bystander response capacity and does not address other contributors to OHCA outcome disparities.

Future research should develop and validate preparedness desert indices that cities could apply to guide resource allocation, evaluate community-embedded training programs with attention to downstream survival outcomes, and examine implementation facilitators for equity-informed preparedness policy.

Conclusion

Geographic disparities in OHCA outcomes are well-documented. Moving from documentation to action requires frameworks that identify modifiable structural factors and direct intervention accordingly. The preparedness desert concept offers such a framework, distinguishing training access from equipment access, emphasizing temporal as well as spatial availability, and locating responsibility in resource distribution rather than individual behavior.

When survival from cardiac arrest correlates with neighborhood demographics, and when the interventions determining survival depend on unequally distributed community resources, preparedness becomes a matter of health equity. The chain of survival begins before EMS arrival; ensuring that the chain functions effectively regardless of where an arrest occurs requires deliberate investment in the communities currently least equipped to respond.

Funding sources

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

CRediT authorship contribution statement

Grace V. Riley: Writing – review & editing, Writing – original draft, Methodology, Investigation, Conceptualization. Mohammad Z. Faizaan: Writing – review & editing, Writing – original draft, Methodology, Investigation, Conceptualization. Chandi Katoch: Writing – review & editing, Writing – original draft, Methodology, Investigation, Conceptualization. Nicholas Cozzi: Writing – review & editing, Validation, Supervision, Conceptualization.

Declaration of competing interest

The authors declare that they have no competing financial or personal interests.