Economic Value of Out-of-Hospital Emergency Care: A Structured Literature Review

Article Outline

• Abstract
• Introduction
  • Background
• Materials and methods
  • Data Sources
  • Study Selection
  • Data Extraction
• Results
  • Data Synthesis
• Discussion
  • Recommendations
• Limitations
• Conclusion
• References
• Copyright

Study objective

The evaluation of the impact of out-of-hospital emergency care is a relatively new research focus. As such, there is a compelling need to determine how finite health care resources should be used in this setting. The objective of this study is to conduct a structured review of published economic evaluations of out-of-hospital emergency care to assess its economic value.

Methods

A structured literature search and structured review of articles pertaining to the economic value of out-of-hospital care was performed. The bibliographic database MEDLINE was searched for pertinent English-language articles published between 1966 and 2003. The search used the medical subject headings “emergency medical services” and “emergency medical technician” and was limited to the subheading “economics” and crossed with the medical subject heading “economics.” The titles generated by this search were systematically reviewed and limited by topic. Abstracts from the identified titles were reviewed to select a final set of pertinent articles. These articles were further limited based on explicit inclusion and exclusion criteria. Authors used a previously published structured evaluation tool to review the final set of identified articles for quality and content.

Results

The initial MEDLINE search identified 3,533 citations. From this set, 535 potentially relevant abstracts were reviewed. From the abstract review, 46 articles were identified, along with an additional 14 from searching the secondary references. Of these 60 articles, 32 met the review inclusion criteria and were subjected to a full structured review. These studies predominantly addressed the cost of cardiac arrest (n=13, 41%), major trauma (n=8, 25%), and emergency medical services treatment in general (n=8, 25%). Only 14 studies considered the costs and consequences of competing alternatives. Of these, 2 were cost-benefit and 12 were cost-effectiveness evaluations. Two of the 14 studies met all 10 criteria for high-quality economic evaluation, whereas 2 others met none.

Conclusion

There is a paucity of out-of-hospital care literature that addresses cost and economic value. The extant literature is limited in scope, poor in quality, and evaluates small subsets of out-of-hospital emergency care costs. Favorable cost-effectiveness has not been firmly established for most aspects of out-of-hospital emergency care.

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Introduction 

Background 

Although few would argue the need for out-of-hospital emergency care within a community, which services and resources should be provided and rapidity of response are topics of considerable debate.¹, ², ³, ⁴, ⁵ As new technologies and skills emerge, decisions about which services a community should provide become even more difficult. Recent studies such as the Ontario Prehospital Life Support project have evaluated the effectiveness of several out-of-hospital interventions.⁶, ⁷, ⁸ However, determining which out-of-hospital interventions to use within a community is more than merely a matter of efficacy and effectiveness. To properly make this determination, cost and cost-effectiveness must also be considered.

Out-of-hospital emergency medical services (EMS) is a relatively young field. Therefore, the level of research has been nascent.⁵, ⁹ The natural evolution of research can be thought of as a continuum from laboratory to efficacy to effectiveness research. Economic evaluations done in a variety of settings are at the end of this continuum.⁶ Once effectiveness has been established and there are at least 2 competing alternatives, economic evaluations are used to determine which alternative is more desirable from a cost perspective. There are myriad out-of-hospital care activities that need to be evaluated from a cost perspective to assist communities in determining how their finite resources should be used.

Interest in out-of-hospital care is high, as evidenced by the recent creation of an out-of-hospital subcommittee for the committee on the Future of Emergency Care in the United States at the Institute of Medicine.¹⁰ Simultaneously, health care costs are increasing at alarming rates.¹¹ In the case of out-of-hospital emergency care, a significant proportion of this cost is often paid by taxpayers, who subsidize the out-of-hospital emergency care system to maintain its availability. For example, in Los Angeles the Reason Public Policy Institute found that the cost per patient transport was $476, and, because of a low rate of fee collection, there was a $12 per-capita tax subsidy required to maintain the system.¹²

The current study was conducted to determine the evidence available on the cost of out-of-hospital emergency care in general, as well as various out-of-hospital interventions. The objective was to systematically review published economic evaluations of out-of-hospital emergency care in order to assess its economic value.

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Materials and methods 

Data Sources 

A structured literature search and a structured review of articles pertaining to the economic value of out-of-hospital emergency care were performed. The initial phase consisted of a search of the bibliographic database MEDLINE to identify relevant English-language articles published between 1966 and 2003. An initial set of references was developed by searching for the medical subject headings “emergency medical services” and “emergency medical technician.” These medical subject headings were limited to the subheading “economics.” A second search was conducted by not limiting the medical subject headings and cross-referencing them by using the “and” command, with a third medical subject heading “economics.” A secondary review was then performed by searching the reference sections of all identified articles for additional relevant articles.

Study Selection 

A single investigator (E.B.L.) reviewed this initial set of reference titles to identify those articles that potentially addressed the cost or economic value of out-of-hospital care. Titles for which it was obvious that out-of-hospital emergency care was not addressed were excluded. We created a working definition of “out-of-hospital emergency care.” It was defined as acute, unscheduled health care delivered outside the hospital by a system that deploys health resources in response to calls to a public safety answering point.

Any title that failed to indicate that a cost or economic evaluation was conducted was excluded. However, to ensure that no relevant articles were missed, any title that could possibly contain a cost or economic evaluation of out-of-hospital emergency care was included for further review.

The abstracts of the selected reference titles were obtained and reviewed by 2 investigators (E.B.L., R.F.M.). Abstracts that indicated that the manuscript might discuss some aspect of the evaluation of out-of-hospital care from a cost or economic perspective were included for further analysis. Again, any questionable abstracts were retained for further review.

The full articles for the selected abstracts were retrieved and reviewed. A single author (E.B.L.) reviewed all of the manuscripts and selected those that met the study definition of out-of-hospital emergency care. Editorials, non–peer-reviewed reports, and review articles were excluded, as well as strictly methods articles. Several investigators (E.B.L., R.F.M., H.G.G., D.W.S.) read the remaining articles and categorized them into 3 groups by using a consensus process. Each categorization was discussed until there was unanimous agreement on all decisions. The categories were those that did any type of cost analysis, those that mentioned the word “cost” but failed to analyze costs, and those that had no mention of cost. The reference sections of all articles that were reviewed were hand searched for additional relevant articles.

Data Extraction 

All articles that reported economic analyses of out-of-hospital EMS were evaluated using a previously published checklist for assessing economic evaluations developed by Drummond et al.¹³ Before the checklist was applied, the articles were classified by whether they were full or partial economic evaluations and by the type of economic evaluation (Figure 1). Drummond defined economic evaluations as full evaluations if they compared the costs and consequences of 2 or more competing alternatives.¹³

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• Figure 1. 

  Method of categorizing full economic evaluations and partial evaluations. By permission of Oxford University Press. Adapted from Methods for the Economic Evaluation of Healthcare Programmes, 2nd edition.¹³

Four types of full economic evaluations were considered: cost-benefit, cost-effectiveness, cost utility, and cost minimization. In a cost-benefit analysis, consequences are measured in dollars. In a cost-effectiveness analysis, consequences are measured in natural units such as the amount of disability or health care resources consumed. In a cost-utility analysis, consequences are measured in quality-adjusted life years (some authors consider a cost-utility analysis to be a cost-effectiveness study with a more comprehensive outcome that accounts for both the quality and quantity of life).¹⁴ A cost-minimization analysis compares 2 competing alternatives with equivalent outcomes to determine which results in the lowest cost. Cost minimization can also be considered a form of cost-effectiveness analysis in which the effectiveness of the competing alternatives is equivalent.

Once the type of evaluation was identified, all references were assessed with a checklist for assessing economic evaluations described by Drummond et al¹³ (Table 1). This checklist was selected because it is comprehensive and widely accepted in the field of health economics.

Table 1. Structured review of articles using the check list for assessing economic evaluations published by Drummond et al.^13⁎

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Results 

Data Synthesis 

The initial MEDLINE search created a reference set of 3,533 references (Figure 2). From this set, 535 references were selected for abstract review, and of these, 46 were selected for a complete manuscript review. Searching the reference sections of selected manuscripts identified an additional 14 references. Of these 60 articles, 32 met the review inclusion criteria and were subjected to a full structured review by several authors (E.B.L., R.F.M., D.W.S., H.G.G.) (Table 1).

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• Figure 2. 

  Article analysis.

Of the 32 studies identified, only 14 were full economic evaluations.¹⁵, ¹⁶, ¹⁷, ¹⁸, ¹⁹, ²⁰, ²¹, ²², ²³, ²⁴, ²⁵, ²⁶, ²⁷, ²⁸ Of these evaluations, 2 were cost-benefit analyses.¹⁵, ¹⁶ The remaining 12 studies were some form of cost-effectiveness study. Three were cost-minimization analyses.¹⁷, ¹⁸, ¹⁹ Three studies used quality-adjusted life years as the outcome.²⁰, ²¹, ²² The remaining 6 studies were traditional cost-effectiveness studies that described the outcome in natural units, primarily cost per life saved.²³, ²⁴, ²⁵, ²⁶, ²⁷, ²⁸

Eighteen of the 32 studies were identified as partial economic evaluations. Eight were cost descriptions: they examined only the cost of 1 alternative, there was no comparison, or the consequences or outcomes were not considered.²⁹, ³⁰, ³¹, ³², ³³, ³⁴, ³⁵, ³⁶ Four were cost-outcome descriptions, meaning that they examined only 1 alternative but considered the costs and the consequences of that alternative.³⁷, ³⁸, ³⁹, ⁴⁰ Six were cost-analyses because they examined the cost of 2 alternative treatments but not the consequences.⁴¹, ⁴², ⁴³, ⁴⁴, ⁴⁵, ⁴⁶

Using the checklist for economic evaluations, the investigators evaluated how well the articles met the checklist criteria (Table 1). Two of the 14 full economic evaluation studies met none of the 10 checklist criteria,¹⁵, ¹⁷ whereas 2 of the studies met all of the checklist criteria.¹⁹, ²¹ The others covered various amounts of the checklist criteria.

Among the 32 studies, 13 (41%) addressed interventions for cardiac arrest, 8 (25%) investigated major trauma (1 study addressed both cardiac arrest and major trauma), and 8 (25%) investigated the general cost of an EMS system. Of the 14 full economic evaluations, 9 (64%) addressed cardiac arrest and 3 (21%) studied major trauma. There was 1 partial analysis that specifically addressed pediatric patients.

Among the 14 full economic evaluations, 4 reported that they calculated costs from the societal perspective. The remaining 10 studies did not clearly state the perspective they were using. However, it appears that 4 used a societal perspective and 6 used the EMS perspective in calculating costs. In terms of comparing the outcomes of the 14 full economic evaluations, only 9 studies reported which calendar year’s dollars were used to calculate costs, thus making difficult the comparison of the other 5 studies to each other or other economic evaluations of interventions (Table 2).

Table 2. Results of the full economic evaluation studies.

EMS, Emergency medical services; QALY, quality adjusted life year; AED, automated external defibrillator; PAD, public access defibrillator; EMT, emergency medicine technician; EMT-D, emergency medicine technician-defibrillator; ALS, advanced life support; ILS, intermediate life support.

Among the 10 analyses in which cost per life saved could be compared, we observed large variations in estimation of cost per life saved, reflecting differences in the comprehensiveness of the costs included, as well as the nature of the interventions considered and their estimated effectiveness. These studies evaluated a range of EMS interventions for cardiac arrest. Using the available data, we next estimated cost per life saved expressed in 2005 dollars (Table 3). For studies that did not state the year of data collection, we assumed that costs were calculated in the year of publication. Insufficient data were available on cost per life saved to include any of the other identified studies in this analysis.

Table 3. Summary of published economic evaluations of EMS interventions for cardiac arrest, with all results adjusted for inflation.

BLS, Basic life support; ICD, implantable cardioverter-defibrillator.

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Discussion 

Only 32 studies that were economic analyses of out-of-hospital care could be identified by rigorous evaluation of the past 38 years of peer-reviewed health care literature. In general, economic evaluations are most useful when there is evidence that an intervention is effective. Only a handful of out-of-hospital interventions have been proven unequivocally to be effective.⁵, ⁴⁷, ⁴⁸ The paucity of science about the effectiveness and cost of out-of-hospital EMS dramatically compromises the ability of communities to optimize the use of limited health care resources.

This comprehensive review yielded only 14 full economic evaluations. The majority of studies were partial economic evaluations that failed to compare competing alternatives or to consider both the costs and consequences of the interventions. Although partial evaluations have some utility, the optimal purpose of an economic evaluation is to assist in making choices about the use of community resources.¹³ Therefore, accurate assessment of the economics of EMS care requires full economic evaluations.

Only 8 of the 14 full economic evaluations met a majority of the criteria for a high-quality analysis. Therefore, there are even fewer studies in the medical literature of sufficient quality to truly assist community decisionmakers. These findings support our initial hypothesis about the near absence of high-quality out-of-hospital-care economic analyses. EMS cost analyses must follow guidelines for the standardization of economic analysis, such as those suggested by the Panel on Cost-effectiveness in Health and Medicine,¹⁴ but there is also a need for a conceptual framework specific to EMS to assist EMS researchers in designing and reporting economic evaluations.

The existing full economic evaluations primarily analyzed cardiac arrest and major trauma. These 2 areas account for only a small percentage of adults transported within the EMS system and an even smaller proportion of pediatric patients transported.⁴⁹ Therefore, the existing economic literature applies to only a small proportion of patients treated by EMS providers. To meaningfully assist communities in determining how their limited resources should best be used, the scope of economic analyses in out-of-hospital emergency care needs to be expanded and the quality improved.

How much a society is willing to pay for EMS will vary between communities and depends, in part, on total funds available. Therefore, different communities are likely to be willing to pay for out-of-hospital care according to their available resources and the competing alternatives, making it difficult to create a universal definition of what incremental cost should be considered a decisionmaking criterion for different EMS systems. It also means that the cost of readiness may be higher in some communities compared to others because of their system demands (eg, minimum response times).

Finally, because of the heterogeneous nature of out-of-hospital emergency care agencies, the effectiveness of a given intervention can be highly variable between agencies.⁵⁰ This factor makes it difficult to determine overall cost-effectiveness for a given intervention across all out-of-hospital emergency care agency types.

To our knowledge, this is the first comprehensive literature search on the economic evaluation of out-of-hospital emergency care. It included an objective assessment of the literature conducted by multiple authors using previously validated criteria for identifying high-quality analyses. The state of the literature on economic evaluation of EMS is poor.

Recommendations 

Future evaluations of the economics of out-of-hospital emergency care interventions should apply rigorous methods to define the population under consideration, the intervention, what it is being compared to, the perspective of the study, the effects of the intervention and its alternatives, and their costs.¹⁴

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Limitations 

This study was a comprehensive literature search that applied a priori qualitative criteria. However, it had several limitations. The existing literature is sparse. It is available for only a few interventions. The methods used were variable between studies, complicating our ability to pool the results meaningfully. Comparisons were even further complicated by the variability between studies in terms of time and place.

Our search was limited in that we restricted it to only published English-language literature because of the expense of translation and our inability to identify unpublished studies. Further, because an expert panel conducted this review, it is limited by the biases inherent in a review by only a handful of individuals. However, because consensus required unanimity among all the reviewers and explicit review criteria were used, these biases were limited.

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Conclusion 

In conclusion, there is a paucity of literature that addresses the economics of out-of-hospital emergency care. The existing literature is of poor quality, limited to a narrow scope, and does not reflect the broad array of care provided within EMS systems. A conceptual framework for evaluating costs and consequences of care delivered in the out-of-hospital setting is needed. Future studies should evaluate the costs and consequences of out-of-hospital interventions by using high-quality methods. Only with the development of the methodologies for this purpose will the much-needed understanding of how to optimize EMS care be possible.

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References 

1. Stiell IG , Wells GA , Spaite DW , et al.   The Ontario Prehospital Advanced Life Support (OPALS) Study, part II: rationale and methodology for trauma and respiratory distress patients: OPALS Study Group . Ann Emerg Med . 1999;34:256–262
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (77 KB)
   • CrossRef
2. Stiell IG , Wells GA , Spaite DW , et al.   The Ontario Prehospital Advanced Life Support (OPALS) Study (rationale and methodology for cardiac arrest patients) . Ann Emerg Med . 1998;32:180–190
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (80 KB)
   • CrossRef
3. Cone DC , Lerner EB , Yealy DM . Prehospital care research (the basics) . Prehosp Emerg Care . 2002;6:S2–S8
   • View In Article
   • MEDLINE
   • CrossRef
4. Seidel JS , Henderson D , Tittle S , et al.   Priorities for research in emergency medical services for children (results of a consensus conference) . Ann Emerg Med . 1999;33:206–210
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (57 KB)
   • CrossRef
5. Sayre MR , White LJ , Brown LH , et al.   National EMS research agenda . Prehosp Emerg Care . 2002;6:S1–S43
   • View In Article
   • MEDLINE
   • CrossRef
6. Stiell IG , Wells GA , Field BJ , et al.   Improved out-of-hospital cardiac arrest survival through the inexpensive optimization of an existing defibrillation program: OPALS Study Phase II: Ontario Prehospital Advanced Life Support . JAMA . 1999;281:1175–1181
   • View In Article
   • MEDLINE
   • CrossRef
7. Stiell IG , Wells GA , DeMaio VJ , et al.   Modifiable factors associated with improved cardiac arrest survival in a multicenter basic life support/defibrillation system: OPALS Study Phase I results: Ontario Prehospital Advanced Life Support . Ann Emerg Med . 1999;33:44–50
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (82 KB)
   • CrossRef
8. Stiell IG , Wells GA , Hebert PC , et al.   Association of drug therapy with survival in cardiac arrest (limited role of advanced cardiac life support drugs) . Acad Emerg Med . 1995;2:264–273
   • View In Article
   • MEDLINE
   • CrossRef
9. Spaite DW , Criss EA , Valenzuela TD , et al.   Emergency medical service systems research (problems of the past, challenges of the future) . Ann Emerg Med . 1995;26:146–152
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (717 KB)
   • CrossRef
10. Institute of Medicine. The future of emergency care: subcommittee on prehospital emergency medical services [Institute of Medicine Web site]. Available at: http://www.iom.edu/project.asp?id=20238. Accessed October 10, 2005.
    • View In Article
11. Sloan F . Valuing Health Care . Cambridge, UK: Cambridge University Press; 1995;
    • View In Article
12. Eggers W. Competitive government for a competitive Los Angeles [Reason Public Policy Institute Web site]. Available at: http://www.rppi.org/es182.html. Accessed October 10, 2005.
    • View In Article
13. Drummond M , O’Brien B , Stoddart G , et al.   In: Methods for the Economic Evaluation of Health Care Programmes . 2nd ed.. Oxford, UK: Oxford University Press; 1997;
    • View In Article
14. Gold MR , Siegel JE , Russell LB , et al.   Cost-effectiveness in Health and Medicine . Oxford, UK: Oxford University Press; 1996;
    • View In Article
15. Riediger G , Fleischmann-Sperber T . Efficiency and cost-effectiveness of advanced EMS in West Germany . Am J Emerg Med . 1990;8:76–80
    • View In Article
    • MEDLINE
    • CrossRef
16. Cretin S . Cost-benefit of treatment and prevention of myocardial infarction . Health Serv Res . 1977;12:174–189
    • View In Article
    • MEDLINE
17. De Wing MD , Curry T , Stephenson E , et al.   Cost-effective use of helicopters for the transportation of patients with burn injuries . J Burn Care Rehabil . 2000;21:535–540
    • View In Article
    • MEDLINE
    • CrossRef
18. Brazier J , Nicholl J , Snooks H . The cost and effectiveness of the London helicopter emergency medical service . J Health Serv Res Policy . 1996;1:232–237
    • View In Article
    • MEDLINE
19. Turner J , Nicholl J , Webber L , et al.   A randomised controlled trial of prehospital intravenous fluid replacement therapy in serious trauma . Health Tech Assess . 2000;4:1–57
    • View In Article
20. Nichol G , Valenzuela T , Roe D , et al.   Cost-effectiveness of defibrillation by targeted responders in public settings . Circulation . 2003;108:697–703
    • View In Article
    • CrossRef
21. Nichol G , Laupacis A , Stiell IG , et al.   Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest . Ann Emerg Med . 1996;27:711–720
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (996 KB)
22. Nichol G , Hallstrom AP , Ornato JP , et al.   Potential cost-effectiveness of public access defibrillation in the United States . Circulation . 1998;97:1315–1320
    • View In Article
    • MEDLINE
23. Jermyn BD . Cost-effectiveness analysis of a rural/urban first-responder defibrillation program . Prehosp Emerg Care . 2000;4:43–47
    • View In Article
    • MEDLINE
    • CrossRef
24. Ornato JP , Craren EJ , Gonzalez ER , et al.   Cost-effectiveness of defibrillation by emergency medical technicians . Am J Emerg Med . 1988;6:108–112
    • View In Article
    • MEDLINE
    • CrossRef
25. Urban N , Bergner L , Eisenberg MS . The costs of a suburban paramedic program in reducing deaths due to cardiac arrest . Med Care . 1981;19:379–392
    • View In Article
    • MEDLINE
    • CrossRef
26. Hallstrom A , Eisenberg MS , Bergner L . Modeling the effectiveness and cost-effectiveness of an emergency service system . Soc Sci Med . 1981;15C:13–17
    • View In Article
27. Forrer CS , Swor RA , Jackson RE , et al.   Estimated cost effectiveness of a police automated external defibrillator program in a suburban community (7 years’ experience) . Resuscitation . 2002;52:23–29
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (93 KB)
    • CrossRef
28. Valenzuela TD , Criss EA , Spaite D , et al.   Cost-effectiveness analysis of paramedic emergency medical services in the treatment of prehospital cardiopulmonary arrest . Ann Emerg Med . 1990;19:1407–1411
    • View In Article
    • Abstract
    • Full-Text PDF (482 KB)
    • CrossRef
29. Suchard JR , Fenton FR , Powers RD . Medicare expenditures on unsuccessful out-of-hospital resuscitations . J Emerg Med . 1999;17:801–805
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (74 KB)
    • CrossRef
30. Rosemurgy AS , Norris PA , Olson SM , et al.   Prehospital traumatic cardiac arrest (the cost of futility) . J Trauma Injury Infect Crit Care . 1993;35:468–473
    • View In Article
31. Daberkow SG . Location and cost of ambulances serving a rural area . Health Serv Res . 1977;12:299–311
    • View In Article
    • MEDLINE
32. Pascarelli EF , Katz IB . Planning and developing a prehospital mobile intensive care system in an urban setting . Am J Public Health . 1978;68:389–393
    • View In Article
    • MEDLINE
    • CrossRef
33. Kriegsman W , Anthes W . The financial impact of alcohol-related emergencies on a rural EMS system . Alaska Med . 1998;40:7–11
    • View In Article
    • MEDLINE
34. Altintas KH , Bilir N , Tuleylioglu M . Costing of an ambulance system in a developing country, Turkey (costs of Ankara Emergency Aid and Rescue Services’ (EARS) ambulance system) . Eur J Emerg Med . 1999;6:355–362
    • View In Article
    • MEDLINE
35. Snooks HA , Nicholl JP , Brazier JE , et al.   The costs and benefits of helicopter emergency ambulance services in England and Wales . J Public Health Med . 1996;18:67–77
    • View In Article
    • MEDLINE
36. Jakobsson J , Nyquist O , Rehnqvist N , et al.   Cost of a saved life following out-of-hospital cardiac arrest resuscitated by specially trained ambulance personnel . Acta Anaesthesiol Scand . 1987;31:426–429
    • View In Article
    • MEDLINE
    • CrossRef
37. Kurola J , Wangel M , Uusaro A , et al.   Paramedic helicopter emergency service in rural Finland (do benefits justify the cost?) . Acta Anaesthesiol Scand . 2002;46:779–784
    • View In Article
    • MEDLINE
    • CrossRef
38. Gearhart PA , Wuerz R , Localio AR . Cost-effectiveness analysis of helicopter EMS for trauma patients . Ann Emerg Med . 1997;30:500–506
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (647 KB)
39. Bur A , Kittler H , Sterz F , et al.   Effects of bystander first aid, defibrillation and advanced life support on neurologic outcome and hospital costs in patients after ventricular fibrillation cardiac arrest . Intensive Care Med . 2001;27:1474–1480
    • View In Article
    • MEDLINE
    • CrossRef
40. Hauswald M , Yeoh E . Designing a prehospital system for a developing country (estimated cost and benefits) . Am J Emerg Med . 1997;15:600–603
    • View In Article
    • Abstract
    • Full-Text PDF (447 KB)
    • CrossRef
41. Brady WJ , Hennes H , Wolf A , et al.   Pattern of basic life support ambulance use in an urban pediatric population . Am J Emerg Med . 1996;14:250–253
    • View In Article
    • Abstract
    • Full-Text PDF (501 KB)
    • CrossRef
42. Lammers RL , Roth BA , Utecht T . Comparison of ambulance dispatch protocols for nontraumatic abdominal pain . Ann Emerg Med . 1995;26:579–589
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (944 KB)
    • CrossRef
43. Fischer AJ , O’Halloran P , Littlejohns P , et al.   Ambulance economics . J Public Health Med . 2000;22:413–421
    • View In Article
    • MEDLINE
44. Lechleuthner A , Koestler W , Voigt M , et al.   Helicopters as part of a regional EMS system (a cost-effectiveness analysis for three EMS regions in Germany) . Eur J Emerg Med . 1994;1:159–166
    • View In Article
    • MEDLINE
45. Bruhn JD , Williams KA , Aghababian R . True costs of air medical vs. ground ambulance systems . Air Med J . 1993;12:262–268
    • View In Article
    • CrossRef
46. Nicholl JP , Beeby NR , Brazier JE . A comparison of the costs and performance of an emergency helicopter and land ambulances in a rural area . Injury . 1994;25:145–153
    • View In Article
    • MEDLINE
    • CrossRef
47. Sayre MR , White LJ , Brown LH , et al.   The national EMS research strategic plan . Prehosp Emerg Care . 2005;9:255–266
    • View In Article
    • MEDLINE
    • CrossRef
48. Delbridge TR , Bailey B , Chew JL , et al.   EMS Agenda for the future: where we are: where we want to be . Prehosp Emerg Care . 1998;2:1–12
    • View In Article
    • MEDLINE
    • CrossRef
49. Maio RF , Garrison HG , Spaite DW , et al.   Emergency Medical Services Outcomes Project I (EMSOP I) (prioritizing conditions for outcomes research) . Ann Emerg Med . 1999;33:423–432
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (84 KB)
    • CrossRef
50. Eisenberg MS , Horwood BT , Cummins RO , et al.   Cardiac arrest and resuscitation (a tale of 29 cities) . Ann Emerg Med . 1990;19:179–186
    • View In Article
    • Abstract
    • Full-Text PDF (900 KB)
    • CrossRef