The way back home: The invisible burden of the emergency healthcare services.

Ambulance services around the world vary according to regional, cultural and socioeconomic conditions. Many countries apply different health policies locally. In Turkey, transportation from hospital to home has started to form an important part of ambulance services in recent years. The increase in the number of patients whose treatment has been completed and waiting to be referred may hinder the work of the emergency services. The aim of this study was to examine the costs, indications, and impact on workload of patients sent home by ambulance. Patients were divided into two groups according to the reasons for referral. The distance to home, transport time and cost were calculated according to the reasons for transport. Patients who were transferred to other clinics or hospitals by ambulance were excluded from the study. The findings showed that the hospital-to-home transfer rate during the study period was 11.4%. Although 9.7% of all cases transferred from our hospital to home were due to social indications, these cases accounted for 16.26% of the total costs. These results suggest that providing home transport services to selected patient groups for medical reasons should be seen as part of the treatment. However, the indications for home transport should not be exceeded and an additional burden should not be placed on the fragile health service.

Trends in ambulance transports and costs among Medicare beneficiaries, 2007-2018.

BACKGROUND: The primary purpose of this study was to evaluate trends in ambulance utilization and costs among Medicare beneficiaries from 2007 to 2018. Community characteristics associated with ambulance use and costs are also explored. METHODS: Aggregated county-level fee-for-service (FFS) Medicare beneficiary claims data from 2007 to 2018 were used to assess ambulance transports per 1000 FFS Medicare beneficiaries and standardized inflation-adjusted ambulance costs. Multivariable linear mixed models were used to quantify trends in ambulance utilization and costs and to control for confounders. RESULTS: A total of 37,675 county-years were included from 2007 to 2018. Ambulance transports per 1000 beneficiaries increased 15% from 299 (95% CI: 291.63, 307.30) to 345 (95% CI: 336.91, 353.10) from 2007 to 2018. Inflation-adjusted standardized per user costs exhibited an increasing (1.04, 95% CI: 1.04, 1.05), but non-linear relationship (0.996, 95% CI: 0.996, 0.996) over time with costs peaking in 2012. Indicators of lower socioeconomic status (SES) were associated with increases in both ambulance events and costs (p < .0001). A higher prevalence of Medicare beneficiaries utilizing Skilled Nursing Facilities was associated with increased levels of ambulance events per 1000 beneficiaries (95% CI: 8.06, 10.63). Rural location was associated with a 38% increase in ambulance costs (95% CI 1.30-1.47) compared to urban location. CONCLUSIONS: Numerous policy solutions have been proposed to address growing ambulance costs in the Medicare program. While ambulance transports and costs continue to increase, a bend in the ambulance cost curve is detected suggesting that one or more policies altered Medicare ambulance costs, although utilization has continued to grow linearly. Ambulance use and costs vary significantly with community-level factors. As policy makers consider how to address growing ambulance use and costs, targeting identified community-level factors associated with greater costs and utilization, and their root causes, may offer a targeted approach to addressing current trends.

Association between ambulance use and hospitalization costs among heart failure patients.

Heart failure is the main cause of hospitalization, which burdens the healthcare system. Although many hospitalizations for heart failure follow ambulance use, it is unknown whether ambulance use increases hospitalization costs. Using the Diagnosis Procedure Combination database in Japan, we examined all hospitalizations of patients with heart failure from April 2014 to March 2015. Patients were divided into those with and those without ambulance use. We performed a multiple regression analysis to examine the association between ambulance use and total hospitalization costs, adjusting for age, sex, length of day, and activities of daily living. We identified 126,067 hospitalizations for heart failure. The percentages of ambulance use were 29%, 27%, 30%, and 50% among patients with NYHA Functional Classification I, II, III, and IV, respectively. For patients categorized as NYHA I (n = 9,700), multiple linear regression analysis revealed that ambulance use was significantly associated with higher hospitalization cost (coefficient 723 USD; 95% confidence interval 109-1337; p = 0.021). Even for heart failure patients with NYHA I, ambulances were frequently used. Ambulance use was independently associated with increased hospital costs. Future research is needed on transitional care to limit unnecessary ambulance use.

Publicly funded interfacility ambulance transfers for surgical and obstetrical conditions: A cross sectional analysis in an urban middle-income country setting.

INTRODUCTION: Interfacility transfers may reflect a time delay of definitive surgical care, but few studies have examined the prevalence of interfacility transfers in the urban low- and middle-income (LMIC) setting. The aim of this study was to determine the number of interfacility transfers required for surgical and obstetric conditions in an urban MIC setting to better understand access to definitive surgical care among LMIC patients. METHODS: A retrospective analysis of public interfacility transfer records was conducted from April 2015 to April 2016 in Cali, Colombia. Data were obtained from the single municipal ambulance agency providing publicly funded ambulance transfers in the city. Interfacility transfers were defined as any patient transfer between two healthcare facilities. We identified the number of transfers for patients with surgical conditions and categorized transfers based on patient ICD-9-CM codes. We compared surgical transfers from public vs. private healthcare facilities by condition type (surgical, obstetric, nonsurgical), transferring physician specialty, and transfer acuity (code blue, emergent, urgent and nonurgent) using logistic regression. RESULTS: 31,659 patient transports occurred over the 13-month study period. 22250 (70.2%) of all transfers were interfacility transfers and 7777 (35%) of transfers were for patients with surgical conditions with an additional 2,244 (10.3%) for obstetric conditions. 49% (8660/17675) of interfacility transfers from public hospitals were for surgical and obstetric conditions vs 32% (1466/4580) for private facilities (P<0.001). The most common surgical conditions requiring interfacility transfer were fractures (1,227, 5.4%), appendicitis (913, 4.1%), wounds (871, 3.9%), abdominal pain (818, 3.6%), trauma (652, 2.9%), and acute abdomen (271, 1.2%). CONCLUSION: Surgical and obstetric conditions account for nearly half of all urban interfacility ambulance transfers. The most common reasons for transfer are basic surgical conditions with public healthcare facilities transferring a greater proportion of patient with surgical conditions than private facilities. Timely access to an initial healthcare facility may not be a reliable surrogate of definitive surgical care given the substantial need for interfacility transfers.

[Nomadism of patients treated by radiotherapy in Île-de-France: Does our health system have as much money to waste?] / Nomadisme des patients traités par radiothérapie en Île-de-France : notre système de santé a-t-il autant d'argent à gaspiller ?

PURPOSE: Human, material, and financial resources being limited, the organization of the care system must allow an efficient allocation of resources. The management of cancers leads to specific and repetitive care for which the reimbursement of transport costs represents a high cost. We carried out an analysis of the additional transport costs, linked to the care of patients in Île-de-France, in a center other than the radiotherapy center closest to their home. MATERIALS AND METHODS: Using data from the Île-de-France Regional Health Agency, we have created a model evaluating the additional cost linked to transport generated by the care of a radiotherapy patient far from his home. In order to take into account the uncertainties linked to the hypotheses made in the development of the model, we carried out deterministic and probabilistic sensitivity analyzes. RESULTS: In the base case, the additional annual cost related to transport was 841,176 euros in Île-de-France. The probabilistic sensitivity analysis reports a total annual additional cost of 2,817,481 euros. CONCLUSION: Our results are similar to a report from the General Inspectorate of Social Affairs published in July 2011, which then pointed to an additional cost of between 4 and 6 million euros annually. The long-term care of cancer patients from their homes contributes to a deterioration in the quality of life linked to travel times, a delay in the care of potential treatment complications, and the spread of infectious diseases, such as COVID-19, and bacteria resistant to antibiotics.

Impact of a novel community testing pathway for people with suspected COVID-19 in Wales: a cost-minimisation analysis.

OBJECTIVE: To compare National Health Service (NHS) organisations' testing pathways for patients with suspected COVID-19 in the community versus standard hospital testing practices. PERSPECTIVE: NHS commissioners and services. METHODS: During the containment phase of the COVID-19 pandemic we developed a community model pathway for COVID-19 testing in Wales with testing teams undertaking swabbing for COVID-19 in individuals' usual place of residence. We undertook a cost-minimisation analysis comparing the costs to the NHS in Wales of community testing for COVID-19 versus standard hospital testing practices and ambulance conveyancing. We analysed data from patients with suspected COVID-19 between January and February 2020 and applied assumptions of costs from national contractual and reference costs for ambulances, staffing and transportation with market costs at the time of publication. RESULTS: 177 patients with suspected COVID-19 underwent community testing via local NHS organisations between January and February 2020 with a mean age of 46.1 (IQR 27.5-56.3). This was 92% of total patients who were tested for COVID-19 during this period. We estimate, compared with standard hospital testing practices, cash savings in improved productivity for the NHS of £24,539 during this time period, in addition to further non-monetised benefits for hospital and ambulance flow. CONCLUSIONS: Community testing for COVID-19 in Wales is now an established pathway and continues to bring benefits for patients, local healthcare organisations and the NHS. Further application of this model in other settings and to other infectious diseases may herald promising returns.

Needs assessment of emergency medical and rescue services in Abuja/Nigeria and environs.

BACKGROUND: Nigeria is ranked second highest in the rate of road accidents and other emergencies (Deaths, disabilities) among 193 countries of the world. There is therefore the need for analyzing Emergency Medical Rescue Services (EMRS) in the country to identify options for improvement. METHOD: The study was conducted from February, 2016 to March, 2017 in three EMRS organizations (FRSC, NEMA and MAITAMA Hospital) located in Abuja. The structure, resources, process of EMRS activities and outcome (delay times, case fatality as well as victims and service-providers satisfaction with services) were assessed through observation, time measurements and interviews. RESULTS: FRSC and NEMA offers (Road Traffic Injury) RTI and Disaster services, the ambulances consist of Intensive Care Unit(ICU) buses, Helicopters, Speed boats, motorbikes and other specialized vehicles. Mortality and morbidity recorded for 2016 was 1.1 and 2% respectively. MAITAMA is a specialist centre that offers general medical services. A total number 1227(88.8%) lives were saved during the observational period by three organizations, 60(4.9%) deaths, 132 (9.6%) disabilities, 793 (57.2%) NCDs and 593(42.8%) RTI. CONCLUSION: Non-communicable diseases (NCDs) cause many deaths and morbidities in the developing world compared to infectious diseases. There is need for total revamping and education of EMRS institutions in Nigeria and Low- Middle Income Countries (LMICs). Abuja and its surroundings suffers from delays in rapid emergency services, lack of adequate awareness, functional ambulances, minimal specialists and inadequate consumables lead to the loss of many lives.

Did UberX reduce ambulance volume?

Ambulances are a vital part of emergency medical services. However, they come in single, high intervention form, which is at times unnecessary, resulting in excessive costs for patients and insurers. In this paper, we ask whether UberX's entry into a city caused substitution away from traditional ambulances for low-risk patients, reducing overall volume. Using a city-panel over-time and leverage that UberX enter markets sporadically over multiple years, we find that UberX entry reduced the per capita ambulance volume by at least 6.7%. Our result is robust to numerous specifications.

Effect of predicted travel time to trauma care on mortality in major trauma patients in Nova Scotia

Background: Trauma is a leading contributor to the burden of disease in Canada, accounting for more than 15 000 deaths annually. Although caring for injured patients at designated trauma centres (TCs) is consistently associated with survival benefits, it is unclear how travel time to definitive care influences outcomes. Using a population-based sample of trauma patients, we studied the association between predicted travel time (PTT) to TCs and mortality for patients assigned to ground transport. Methods: Victims of penetrating trauma or motor vehicle collisions (MVCs) in Nova Scotia between 2005 and 2014 were identified from a provincial trauma registry. We conducted cost distance analyses to quantify PTT for each injury location to the nearest TC. Adjusted associations between TC access and injury-related mortality were then estimated using logistic regression. Results: Greater than 30 minutes of PTT to a TC was associated with a 66% increased risk of death for MVC victims (p = 0.045). This association was lost when scene deaths were excluded from the analysis. Sustaining a penetrating trauma greater than 30 minutes from a TC was associated with a 3.4-fold increase in risk of death. Following the exclusion of scene deaths, this association remained and approached significance (odds ratio 3.48, 95% confidence interval 0.98­14.5, p = 0.053). Conclusion: Predicted travel times greater than 30 minutes were associated with worse outcomes for victims of MVCs and penetrating injuries. Improving communication across the trauma system and reducing prehospital times may help optimize outcomes for rural trauma patients.

Contexte: Les traumatismes contribuent pour une bonne part au fardeau de la maladie au Canada; on leur attribue plus de 15 000 décès annuellement. Même si les soins prodigués aux patients victimes de traumatismes dans les centres de traumatologie désignés (CTD) sont toujours associés à des gains au plan de la survie, on ignore quelle est l'influence du temps de transfert vers le CTD sur l'issue. À partir d'un échantillon de patients polytraumatisés basé dans la population, nous avons analysé le lien entre le temps de transfert prévu (TTP) vers le CTD et la mortalité des patients transportés par voie terrestre. Méthodes: On a identifié les victimes de traumatismes pénétrants ou d'accidents de la route en Nouvelle-Écosse entre 2005 et 2014 à partir d'un registre provincial de traumatologie. Nous avons analysé la distance de coût pour quantifier le TTP à partir de chaque scène vers le CTD le plus proche. Les liens ajustés entre l'accès au CTD et la mortalité liée au traumatisme ont ensuite été estimés par régression logistique. Résultats: Un délai de TTP de plus de 30 minutes pour arriver au CTD a été associé à un accroissement de 66 % du risque de décès chez les patients polytraumatisés (p = 0,045). Ce lien s'annulait si on excluait de l'analyse les décès survenus sur la scène de l'accident. Subir un traumatisme ouvert à plus de 30 minutes de distance d'un CTD a été associé à une augmentation par un facteur de 3,4 du risque de décès. Une fois les décès sur la scène de l'accident exclus, ce lien a persisté et s'est rapproché du seuil de signification (rapport des cotes 3,48, intervalle de confiance de 95 % 0,98­14,5, p = 0,053). Conclusion: Des temps de transfert prévus supérieurs à 30 minutes ont été associés une issue plus défavorable pour les victimes d'accidents de la route et de traumatismes pénétrants. L'amélioration de la communication entre les divers éléments du système de traumatologie et la réduction du temps préhospitalier pourrait optimiser l'issue pour les patients victimes de traumatismes en région rurale.

Economic Benefit of "Modern" Nonemergency Medical Transportation That Utilizes Digital Transportation Networks.

OBJECTIVES: To determine the economic benefit of "modern" nonemergency medical transportation (NEMT) that utilizes digital transportation networks compared with traditional NEMT in the United States. METHODS: We used the National Academies' NEMT cost-effectiveness model to perform a baseline cost savings analysis for provision of NEMT for transportation-disadvantaged Medicaid beneficiaries. On the basis of a review of the literature, commercial information, and structured expert interviews, we performed a sensitivity analysis to determine the incremental economic benefit of using modern NEMT. We estimated confidence intervals (CIs) by using Monte Carlo simulation. RESULTS: Total annual net savings for traditional NEMT in Medicaid was approximately $4 billion. For modern NEMT, estimated savings on ride costs varied from 30% to 70%. In comparison with traditional, modern NEMT was estimated to save $268 per expected user (95% CI = $248, $288 per member per year) and $537 million annually (95% CI = $496 million, $577 million) when scaled nationally. CONCLUSIONS: Modern NEMT has the potential to yield greater cost savings than traditional NEMT while also improving patient experience. Public Health Implications: Barriers to NEMT are a health risk affecting high-need, economically disadvantaged patients. Economic arguments supporting modern NEMT are important given decreased support for human services spending.

What do we know about the healthcare costs of extreme heat exposure? A comprehensive literature review.

Exposure to extreme heat can lead to a range of heat-related illnesses, exacerbate pre-existing health conditions and cause increased demand on the healthcare system. A projected increase in temperature may lead to greater healthcare expenditure, however, at present the costs of heat-related healthcare utilization is under-researched. This study aims to review the literature on heat-related costs for the healthcare system with a focus on ED visits, hospitalization, and ambulance call-outs. PubMed, Scopus, and Embase were used to search relevant literature from database inception to December 2017 and limited to human studies and English language. After screening, a total of ten papers were identified for final inclusion. In general, the healthcare costs of heat extremes have been poorly investigated in developed countries and not reported in developing countries where the largest heat-vulnerable populations reside. Studies showed that exposure to extreme heat was causing a substantial economic burden on healthcare systems. Females, the elderly, low-income families, and ethnic minorities had the highest healthcare costs on a range of health services utilization. Although a few studies have estimated heat healthcare costs, none of them quantified the temperature-healthcare cost relationship. There is a need to systematically examine heat-attributable costs for the healthcare system in the context of climate change to better inform heat-related policy making, target interventions and resource allocation.

A review on ambulance offload delay literature.

Ambulance offload delay (AOD) occurs when care of incoming ambulance patients cannot be transferred immediately from paramedics to staff in a hospital emergency department (ED). This is typically due to emergency department congestion. This problem has become a significant concern for many health care providers and has attracted the attention of many researchers and practitioners. This article reviews literature which addresses the ambulance offload delay problem. The review is organized by the following topics: improved understanding and assessment of the problem, analysis of the root causes and impacts of the problem, and development and evaluation of interventions. The review found that many researchers have investigated areas of emergency department crowding and ambulance diversion; however, research focused solely on the ambulance offload delay problem is limited. Of the 137 articles reviewed, 28 articles were identified which studied the causes of ambulance offload delay, 14 articles studied its effects, and 89 articles studied proposed solutions (of which, 58 articles studied ambulance diversion and 31 articles studied other interventions). A common theme found throughout the reviewed articles was that this problem includes clinical, operational, and administrative perspectives, and therefore must be addressed in a system-wide manner to be mitigated. The most common intervention type was ambulance diversion. Yet, it yields controversial results. A number of recommendations are made with respect to future research in this area. These include conducting system-wide mitigation intervention, addressing root causes of ED crowding and access block, and providing more operations research models to evaluate AOD mitigation interventions prior implementations. In addition, measurements of AOD should be improved to assess the size and magnitude of this problem more accurately.

Pre-hospital ambulance care of patients following a suspected seizure: A cross sectional study.

PURPOSE: We aimed to investigate the characteristics of patients presenting to the ambulance service with suspected seizures, the costs of managing these patients and the factors which predicted transport to hospital. METHODS: We employed a cross-sectional design using routine clinical data from a UK regional ambulance service. Logistic regression was used to identify predictors of transport to hospital from ambulance response times, demographics, clinical (physiological) findings and treatments. RESULTS: There were 177,715 emergency incidents recorded in 2011/12 of which 2.9% (5139/177,715) were classified as seizures by ambulance call handlers and 2.7% (4884/177,715) by paramedics on the scene. Suspected seizures were the seventh most common call type. The annual cost of managing these incidents was £890,148. Clinical and physiological variables were normal for most patients. 59.3% (2894/4884) of patients were transported to hospital. 1/4884 (0.02%) patient died. Administration of diazepam, insertion of an airway and pyrexia perfectly predicted transport to hospital, tachycardia had a modest association, but other variables were only weak predictors of transport to hospital. CONCLUSIONS: This study shows that most patients after a suspected seizure are not acutely unwell but nevertheless most patients are transported to hospital. Further research is required to determine which factors are important in decisions to transport to hospital and to create evidence-based tools to help paramedics identify patients who could be safely managed without transport to hospital.

A mathematical model for efficient emergency transportation in a disaster situation.

This work focuses on a real-life patient transportation problem derived from emergency medical services (EMS), whereby providing ambulatory service for emergency requests during disaster situations. Transportation of patients in congested traffic compounds already time sensitive treatment. An urgent situation is defined as individuals with major or minor injuries requiring EMS assistance simultaneously. Patients are either (1) slightly injured and treated on site or (2) are seriously injured and require transfer to points of care (PoCs). This paper will discuss enhancing the response-time of EMS providers by improving the ambulance routing problem (ARP). A genetic based algorithm is proposed to efficiently guide the ARP while simultaneously solving two scenarios.

Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Extension of Temporary Moratoria on Enrollment of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Designated Geographic Locations. Extension of temporary moratoria.

This document announces the extension of statewide temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance providers and suppliers and Medicare home health agencies, subunits, and branch locations in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey, as applicable, to prevent and combat fraud, waste, and abuse. This extension also applies to the enrollment of new non-emergency ground ambulance suppliers and home health agencies, subunits, and branch locations in Medicaid and the Children's Health Insurance Program in those states. For purposes of these moratoria, providers that were participating as network providers in one or more Medicaid managed care organizations prior to January 1, 2018 will not be considered "newly enrolling" when they are required to enroll with the State Medicaid agency pursuant to a new statutory requirement, and thus will not be subject to the moratoria.

Examination of Factors that Influence the Operation Income and Expenditure Balance Difference Rate of 20 Educational Foundation Universities.

OBJECTIVES: The objective of this study is to examine the factors that influence the operation income and expenditure balance ratio of school corporations running university hospitals by multiple regression analysis. METHODS: 1. We conducted cluster analysis of the financial ratio and classified the school corporations into those running colleges and universities.2. We conducted multiple regression analysis using the operation income and expenditure balance ratio of the colleges as the variables and the Diagnosis Procedure Combination data as the explaining variables.3. The predictive expression was used for multiple regression analysis. RESULTS: 1. The school corporations were divided into those running universities (7), colleges (20) and others. The medical income ratio and the debt ratio were high and the student payment ratio was low in the colleges.2. The numbers of emergency care hospitalizations, operations, radiation therapies, and ambulance conveyances, and the complexity index had a positive influence on the operation income and expenditure balance ratio. On the other hand, the number of general anesthesia procedures, the cover rate index, and the emergency care index had a negative influence.3. The predictive expression was as follows.Operation income and expenditure balance ratio = 0.027 × number of emergency care hospitalizations + 0.005 × number of operations + 0.019 × number of radiation therapies + 0.007 × number of ambulance conveyances - 0.003 × number of general anesthesia procedures + 648.344 × complexity index - 5877.210 × cover rate index - 2746.415 × emergency care index - 38.647Conclusion: In colleges, the number of emergency care hospitalizations, the number of operations, the number of radiation therapies, and the number of ambulance conveyances and the complexity index were factors for gaining ordinary profit.

Cost-effectiveness of an ambulance-based referral system for emergency obstetrical and neonatal care in rural Ethiopia.

BACKGROUND: To estimate the cost-effectiveness of an ambulance-based referral system an dedicated to emergency obstetrics and neonatal care (EmONC) in remote sub-Saharan settings. METHODS: In this prospective study performed in Oromiya Region (Ethiopia), all obstetrical cases referred to the hospital with the ambulance were consecutively evaluated during a three-months period. The health professionals who managed the referred cases were requested to identify those that could be considered as undoubtedly effective. Pre and post-referral costs included those required to run the ambulance service and the additional costs necessary for the assistance in the hospital. Local life expectancy tables were used to calculate the number of year saved. RESULTS: A total of 111 ambulance referrals were recorded. The ambulance was undoubtedly effective for 9 women and 4 newborns, corresponding to 336 years saved. The total cost of the intervention was 8299 US dollars. The cost per year life saved was 24.7 US dollars which is below the benchmarks of 150 and 30 US dollars that define attractive and very attractive interventions. Sensitivity analyses on the rate of effective referrals, on the costs of the ambulance and on the discount rate confirmed the robustness of the result. CONCLUSIONS: An ambulance-based referral system for EmONC in remote sub-Saharan areas appears highly cost-effective.

Geographic Variation in Use of Ambulance Transport to the Emergency Department.

STUDY OBJECTIVE: Evidence on variability in emergency medical services use is limited. We obtain national evidence on geographic variation in the use of ambulance transport to the emergency department (ED) among Medicare enrollees and assess the role of health status, socioeconomic status, and provider availability. METHODS: We used 2010 Medicare claims data for a random sample of 999,999 enrollees aged 66 years and older, and identified ambulance transport and ED use. The main outcome measures were number of ambulance transports to the ED per 100 person-years (ambulance transport rate) and proportion (percentage) of ED visits by ambulance transport by hospital referral regions. RESULTS: The national ambulance transport rate was 22.2 and the overall proportion of ED visits by ambulance was 36.7%. Relative to hospital referral regions in the lowest rate quartile, those in the highest quartile had a 75% higher ambulance transport rate (incidence rate ratio [IRR] 1.75; 95% confidence interval [CI] 1.69 to 1.81) and a 15.5% higher proportion of ED visits by ambulance (IRR 1.155; 95% CI 1.146 to 1.164). Adjusting for health status, socioeconomic status, and provider availability reduced quartile 1 versus quartile 4 difference in ambulance transport rate by 43% (IRR 1.43; 95% CI 1.38 to 1.48) and proportion of ED visits by ambulance by 7% (IRR 1.145; 95% CI 1.135 to 1.155). Among the 3 covariate domains, health status was associated with the largest variability in ambulance transport rate (30.1%), followed by socioeconomic status (12.8%) and provider availability (2.9%). CONCLUSION: Geographic variability in ambulance use is large and associated with variation in patient health status and socioeconomic status.