Author ORCID Identifier

https://orcid.org/0000-0002-6378-3394

Semester

Spring

Date of Graduation

2026

Document Type

Dissertation

Degree Type

PhD

College

School of Public Health

Department

Epidemiology

Committee Chair

Brian Hendricks

Committee Co-Chair

Scott Findley

Committee Member

Ruchi Bhandari

Committee Member

Caroline Groth

Abstract

Spatial analyses using Emergency Medical Services data to inform healthcare.

Jeffrey Pesarsick

Background

Emergency Medical Services (EMS) often serve as the initial entry point for patients into the healthcare system in the United States.  Rural health disparities, geographic isolation, socioeconomic disadvantages, and operational challenges create disparities in access to EMS services.  Disparities include prolonged response times, less resources available, and inequities in levels of care available.  The overall goal of these series of projects was to quantify the extent to which operational challenges in EMS data impact health, and how EMS data could be used to identify neighborhood level trends in disease.  Presented in the three-manuscript format, each study examines disparities through different geographic scales; national, regional, and local.  In aim one we examine the relationship between insurance, geography, and level of EMS care provided in low acuity 9-1-1 responses using a national EMS dataset.  The second aim, using a regional database of helicopter EMS (HEMS) flight requests from critical access hospitals (CAH) in West Virginia (WV) explores the meteorological, temporal, operational, and infrastructure barriers that inhibit successful aeromedical transport.  Our last aim investigates cardiovascular EMS activations to identify differential spatial patterns by age and the impact of suspected overdose on these differences.

Methods

The first aim, “A Cross-Sectional Analysis of ALS/BLS Care in Low Acuity 9-1-1 Responses by Geography and Insurance Status,” utilized 4.3 million EMS response records from the National Emergency Medical Services Information System (NEMSIS) to examine differences in the level of EMS care Basic Life Support (BLS) versus Advanced Life Support (ALS) by patient acuity, insurance and geography.  Multivariable logistic regressing was used to estimate the adjusted odds of low acuity responses receiving ALS care.  The second aim, “Factors Impacting Helicopter Emergency Medical Services Transport from Critical Access Hospitals in West Virginia (2015-2019),” examined 6,429 HEMS interfacility transport requests from CAH in WV.  Meteorological data, geography, hospital infrastructure and temporal variables were examined using logistic regression with regional random effects to identify predictors of barriers to successful aeromedical interfacility transport.  The third aim study, “Age-dependent Geographic Convergence of Overdose and Cardiovascular EMS Calls: A Spatial Point Process Analysis,” analyzed 89,698 EMS activations form Washington County, Pennsylvania.  Poison point process modeling was utilized to examine the spatial intensity of EMS calls for cardiovascular complaints by age and examining how overdose activity impacted these patterns adjusting for population.

Results

Multilevel analyses across all three studies demonstrate consistent patterns of geographic and structural inequities in EMS delivery and access to care.  In the first aim, low acuity EMS responses had significantly lower odds of receiving ALS care (aOR = 0.457, 95% CI [0.454, 0.460]).  Rural geographies and those on public insurances also had lower odds of ALS care among low acuity responses.  In the second aim, 36% of the transport missions from CAH facilities were not completed.  Mission non-completing was significantly associated with the winter season (aOR 1.42, 95% CI [1.17,1.74]), low ceilings and visibility conditions, temperature dewpoint spread of < = 5F had similar odds.  CAHs that did not have an established helipad had higher odds of mission non-completion (aOR = 1.34, 95% CI[1.06,1.70]).  In the third aim, a spatial analysis of Washington County, younger adults (18–45 years) exhibited 84% fewer cardiac EMS activations than older adults; however, every standard deviation increase in overdose activity was associated with a 2% rise in cardiac EMS activations in the younger cohort, suggesting a spatially mediated overlap between substance use and cardiovascular emergencies.

Discussion

Findings across all three studies demonstrated that EMS access and effectiveness are shaped by spatial, socioeconomic, and structural determinants.  In the first aim, rural areas, regardless of insurance, there were increased disparities in level of care provided with less access to ALS-level interventions.  This suggests an underlying systemic inequity in access to EMS care which may be reflective of barriers in rural EMS funding and resource allocation.  This inequality is troubling as many rural communities are already suffering from access to care and poor health conditions.  In the second aim study, structural barriers; lack of helipads at CAH facilities reduced access to definitive care by limiting interfacility transfers.  Meteorological conditions associated with freezing conditions, poor visibility weather conditions, as well as geographic factors, long distance transport resulted in higher odds of mission noncompletion.  These barriers suggest that structural changes, IFR flight rules programs, and alternative transport mechanisms are needed to improve access to care and improve patient outcomes.  In the third aim, modeling suggests an interconnection between substance misuse disorders and cardiovascular disease in younger persons 18-45.  In areas of higher drug overdose calls, there was a disproportionate risk of cardiovascular events in younger adults.  This emphasizes the complex intersection to these diseases and highlights opportunities for additional prevention and treatment strategies.

Together, these studies across three geographic scales demonstrate the remarkable validity and utility of EMS data for public health research.  This dissertation advances the understanding of the complex interactions of geography, operational, and structural inequities interact to influence prehospital care.  Our findings support the need for integrated solutions such as data driven response models, community-based paramedicine programs, updates in hospital infrastructure, expanded telemedicine, and targeted multifaceted prevention programs to improve rural health care access and outcomes.

Download

Included in

Epidemiology Commons

Share

COinS