Cost-effectiveness analysis of paramedic emergency medical services in the treatment of prehospital cardiopulmonary arrest

Validation of the NUE Rule to Predict Futile Resuscitation of Out-of-Hospital Cardiac Arrest

AIM

We validated the NUE rule, using three criteria (Non-shockable initial rhythm, Unwitnessed arrest, Eighty years or older) to predict futile resuscitation of patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We performed a retrospective cohort analysis of all recorded OHCA in Marion County, Indiana, from January 1, 2014 to December 31, 2019. We described patient, arrest, and emergency medical services (EMS) response characteristics, and assessed the performance of the NUE rule in identifying patients unlikely to survive to hospital discharge.

RESULTS

From 2014 to 2019, EMS responded to 4370 patients who sustained OHCA. We excluded 329 (7.5%) patients with incomplete data. Median patient age was 62 years (IQR 49 - 73), 1599 (39.6%) patients were female, and 1728 (42.8%) arrests were witnessed. The NUE rule identified 290 (7.2%) arrests, of whom none survived to hospital discharge.

CONCLUSION

In external validation, the NUE rule (Non-shockable initial rhythm, Unwitnessed arrest, Eighty years or older) correctly identified 7.2% of OHCA patients unlikely to survive to hospital discharge. The NUE rule could be used in EMS protocols and policies to identify OHCA patients very unlikely to benefit from aggressive resuscitation.

A simple decision rule predicts futile resuscitation of out-of-hospital cardiac arrest

AIM

Resuscitation of cardiac arrest involves invasive and traumatic interventions and places a large burden on limited EMS resources. Our aim was to identify prehospital cardiac arrests for which resuscitation is extremely unlikely to result in survival to hospital discharge.

METHODS

We performed a retrospective cohort analysis of all cardiac arrests in San Mateo County, California, for which paramedics were dispatched, from January 1, 2015 to December 31, 2018, using the Cardiac Arrest Registry to Enhance Survival (CARES) database. We described characteristics of patients, arrests, and EMS responses, and used recursive partitioning to develop decision rules to identify arrests unlikely to survive to hospital discharge, or to survive with good neurologic function.

RESULTS

From 2015-2018, 1750 patients received EMS dispatch for cardiac arrest in San Mateo County. We excluded 44 patients for whom resuscitation was terminated due to DNR directives. Median age was 69 years (IQR 57-81), 563 (33.0%) patients were female, 816 (47.8%) had witnessed arrests, 651 (38.2%) received bystander CPR, 421 (24.7%) had an initial shockable rhythm, and 1178 (69.1%) arrested at home. A simple rule (non-shockable initial rhythm, unwitnessed arrest, and age 80 or greater) excludes 223 (13.1%) arrests, of whom none survived to hospital discharge.

CONCLUSION

A simple decision rule (non-shockable rhythm, unwitnessed arrest, age ≥ 80) identifies arrests for which resuscitation is futile. If validated, this rule could be applied by EMS policymakers to identify cardiac arrests for which the trauma and expense of resuscitation are extremely unlikely to result in survival.

Cost-effectiveness Analysis Appraisal and Application: An Emergency Medicine Perspective

Cost-effectiveness is an important goal for emergency care delivery. The many diagnostic, treatment, and disposition decisions made in the emergency department (ED) have a significant impact upon healthcare resource utilization. Cost-effectiveness analysis (CEA) is an analytic tool to optimize these resource allocation decisions through the systematic comparison of costs and effects of alternative healthcare decisions. Yet few emergency medicine leaders and policymakers have any formal training in CEA methodology. This paper provides an introduction to the interpretation and use of CEA with a focus on application to emergency medicine problems and settings. It applies a previously published CEA to the hypothetical case of a patient presenting to the ED with chest pain who requires risk stratification. This paper uses a widely cited checklist to appraise the CEA. This checklist serves as a vehicle for presenting basic CEA terminology and concepts. General topics of focus include measurement of costs and outcomes, incremental analysis, and sensitivity analysis. Integrated throughout the paper are recommendations for good CEA practice with emphasis on the guidelines published by the U.S. Panel on Cost-Effectiveness in Health and Medicine. Unique challenges for emergency medicine CEAs discussed include the projection of long-term outcomes from emergent interventions, costing ED services, and applying study results to diverse patient populations across various ED settings. The discussion also includes an overview of the limitations inherent in applying CEA results to clinical practice to include the lack of incorporation of noncost considerations in CEA (e.g., ethics). After reading this article, emergency medicine leaders and researchers will have an enhanced understanding of the basics of CEA critical appraisal and application. The paper concludes with an overview of economic evaluation resources for readers interested in conducting ED-based economic evaluation studies.

Barriers to EMS System Evaluation: Problems Associated with Field Data Collection

For more than two decades, emergency medical services (EMS) systems have proliferated primarily based upon governmental impetus and funding at the federal, state, and local levels. Although many of the foundations of patient care rendered in these systems have been based upon intuitive logic, the understanding of the impact on patient outcome is poor, at best. The reasons for the current status are varied, but five issues are preeminent:

1) The authority for the development of these medical systems has been based primarily in political and bureaucratic institutions which have little or no medical expertise;

2) Little attention has been paid to system evaluation, particularly in the area of cost-effectiveness;

3) Few academic medical institutions have become involved in EMS research;

4) Traditional approaches to medical research primarily are disease-specific and are not multidisciplinary. Thus these are not useful for evaluating and understanding the highly complex and uncontrolled environmental interactions that typify EMS systems; and

5) The process of efficiently and reliably collecting accurate data in the prehospital setting is extremely difficult.

The Price of a Helping Hand: Modeling the Outcomes and Costs of Bystander CPR

OBJECTIVE

Early, high-quality, minimally interrupted bystander cardio-pulmonary resuscitation (BCPR) is essential for out-of-hospital cardiac arrest survival. However, rates of bystander intervention remain low in many geographic areas. Community CPR programs have been initiated to combat these low numbers by teaching compression-only CPR to laypersons. This study examined bystander CPR and the cost-effectiveness of a countywide CPR program to improve out-of-hospital cardiac arrest survival.

METHODS

A 2-year retrospective review of emergency medical services (EMS) run reports for adult nontraumatic cardiac arrests was performed using existing prehospital EMS quality assurance data. The incidence and success of bystander CPR to produce prehospital return of spontaneous circulation and favorable neurologic outcomes at hospital discharge were analyzed. The outcomes were paired with cost data for the jurisdiction's community CPR program to develop a cost-effectiveness model.

RESULTS

During the 23-month study period, a total of 371 nontraumatic adult out-of-hospital cardiac arrests occurred, with a 33.4% incidence of bystander CPR. Incremental cost-effectiveness analysis for the community CPR program demonstrated a total cost of $22,539 per quality-adjusted life-year (QALY). A significantly increased proportion of those who received BCPR also had an automated external defibrillator (AED) applied. There was no correlation between witnessed arrest and performance of BCPR. A significantly increased proportion of those who received BCPR were found to be in a shockable rhythm when the initial ECG was performed. In the home setting, the chances of receiving BCPR were significantly smaller, whereas in the public setting a nearly equal number of people received and did not receive BCPR. Witnessed arrest, AED application, public location, and shockable rhythm on initial ECG were all significantly associated with positive ROSC and neurologic outcomes. A home arrest was significantly associated with worse neurologic outcome.

CONCLUSIONS

Cost-effectiveness analysis demonstrates that a community CPR outreach program is a cost-effective means for saving lives when compared to other healthcare-related interventions. Bystander CPR showed a clear trend toward improving the neurologic outcome of survivors. The findings of this study indicate a need for additional research into the economic effects of bystander CPR.

Health care costs related to out-of-hospital cardiopulmonary arrest in Japan

OBJECTIVES

Although cost analyses for emergency care are essential, data on costs of care for out-of-hospital cardiopulmonary arrest (OHCA) are scarce. The present study aimed to analyze health care costs related to OHCA using a nationwide administrative database in Japan.

METHODS

Using the Diagnosis Procedure Combination database in Japan, we identified OHCA patients who were transported to 779 emergency medical centres between July and December in 2008 and 2009. We assessed patient survival and discharge status, receipt of specific treatments, and costs of in-hospital care.

RESULTS

A total of 21,750 OHCA patients were identified. Overall, 59.6% were males, and the average age was 70.3 years. Of them, 1394 (6.4%) resulted in death without attempted resuscitation after hospital arrival (Group A), 14,973 (69.0%) died on admission day despite resuscitation attempts (Group B), 3680 (17.0%) died at ≥2 days after admission despite resuscitation attempts (Group C), 785 (3.6%) survived and were discharged to home (Group D) and 873 (4.0%) survived and discharged to other than home (Group E). The median total costs were $434, $1735, $4869, $28,097 and $31,161 in Groups A to E, respectively. Positive survival status, longer hospital stay and receipt of specific treatments were significant predictors of higher total costs. After adjustment for these factors, higher age was associated with lower costs.

CONCLUSIONS

The findings in the present study add further evidence to existing knowledge about healthcare costs related to OHCA.

A New Model for Evaluating the Impact of Major System Changes on Emergency Air Medical Scene Responses in a Regional EMS System

Hypothesis:

Centralized dispatch data can provide useful information regarding the impact of major air medical system changes in a regional emergency medical services (EMS) system.

Methods:

Prospective evaluation of helicopter dispatch data from a centralized EMS dispatch agency. During the study period, four alterations in the total number of helicopters available to the system occurred (1,2,3,2,3). Statistical analysis consisted of Chi-Square with Yates' correction and comparison of sample proportions with p<.05 considered significant.

Results:

A total of 667 helicopter dispatches occurred during the 20-month study period from April 1989 through November 1990.

Conclusion:

Changes in dispatch patterns could result either from increased availability or alterations in the dispatchers' “threshold” for use based upon a perceived lessening of the need to save a “scarce” resource. Had the second possibility played a significant role, the rate of cancellation by ground personnel after arrival at the scene would be expected to have increased. Since this did not occur, it is likely that the increased use actually was a result of increased availability. In systems that dispatch helicopters prior to arrival of ground personnel, this method of evaluation may provide a useful model for analyzing the impact of major system alterations.

A Cost-Effectiveness Analysis of Pediatric Intraosseous Infusion as a Prehospital Skill

Purpose:

To determine the clinical efficacy, patient volume, and program costs that justify pediatric intraosseous (IO) infusion as a routine skill for the treatment of patients with cardiac arrest in a prehospital system.

Methods:

A decision analytic model was constructed to include patient outcomes and costs to society. Critical variables for the analysis were: 1) time to vascular access; 2) success of vascular access; 3) clinical efficacy (i.e., the percentage of lives saved by early vascular access); 4) number of patients requiring IO annually; and 5) the cost of an IO program. Program costs included training and equipment expenses. Sensitivity analysis, which repeatedly evaluates the model using different values for the critical variables, identified those values at which IO would be cost-effective.

Results:

With an estimated 80% success rate for IO access within five minutes, the cost-per-life-saved would be [US] $161,000. This cost-effectiveness ratio assumed annual program expenses of $2,000 and one patient per year needing IO. The cost-effectiveness ratio also required a clinical efficacy of 2% for vascular access. To prove that the clinical efficacy of vascular access is in fact 2%, epidemiologic studies would require a sample of nearly 9,000 patients.

Conclusions:

This analysis suggests IO probably is cost-effective given a clinical efficacy above 2%. While the true efficacy may be below this value, clinical studies are unlikely to have sufficient size to prove it. Therefore, emergency medical services (EMS) medical directors must make the decision to utilize IO based on their own beliefs about its clinical efficacy. Further, it must be considered in the context of other prehospital programs which may be more cost-effective. Such analyses permit establishment of rational priorities to rank programs in prehospital systems.

The Efficacy of Advanced Life Support: A Review of the Literature

Introduction:

Jurisdictions throughout the United States and some other parts of the world have invested substantial time and resources into creating and sustaining a prehospital advanced life support (ALS) system without knowing whether the efficacy of ALS-level care had been validated scientifically. In recent years, it has become fashionable for speakers before large audiences to declare that there is no scientific evidence for the clinical effectiveness of ALS-level care in the out-of-hospital setting. This study was undertaken to evaluate the evidence that pertains to the efficacy of ALS-level care in the current scientific literature.

Methods:

An extensive review of the available literature was accomplished using computerized and manual means to identify all applicable articles from 1966 to October, 1995. Selected articles were read, abstracted, analyzed, and compiled Each article also was categorized as presenting evidence supporting or refuting the clinical efficacy of ALS-level care, and a list was constructed that pointed to where the preponderance of the evidence lies.

Results:

Research in this field differs widely in terms of methodological sophistication. Of the 51 articles reviewed, eight concluded that ALS-level care is not any more effective than is basic life support, seven concluded that it is effective in some applications but not for others, and the remainder demonstrated effectiveness. The strongest support for ALS-level care was in the area of responses to victims of cardiac arrest, whereas somewhat more divergent findings related to trauma or non condition-specific studies.

Conclusion:

While not unanimous, the predominant finding of recent research into the clinical effectiveness of advanced life support demonstrates improved effectiveness over basic life support for patients with certain pathologies. More outcomes-based research is needed.

Termination of resuscitation of nontraumatic cardiopulmonary arrest: resource document for the National Association of EMS Physicians position statement

In the development of an emergency medical services (EMS) system, medical directors should consider the implementation of protocols for the termination of resuscitation (TOR) of nontraumatic cardiopulmonary arrest. Such protocols have the potential to decrease unnecessary use of warning lights and sirens and save valuable public health resources. Termination-of-resuscitation protocols for nontraumatic cardiopulmonary arrest should be based on the determination that an EMS provider did not witness the arrest, there is no shockable rhythm identified, and there is no return of spontaneous circulation (ROSC) prior to EMS transport. Further research is needed to determine the need for direct medical oversight in TOR protocols and the duration of resuscitation prior to EMS providers' determining that ROSC will not be achieved. This paper is the resource document to the National Association of EMS Physicians position statement on the termination of resuscitation for nontraumatic cardiopulmonary arrest.

Hospital costs and revenue are similar for resuscitated out-of-hospital cardiac arrest and ST-segment acute myocardial infarction patients

OBJECTIVES

Care provided to patients who survive to hospital admission after out-of-hospital cardiac arrest (OOHCA) is sometimes viewed as expensive and a poor use of hospital resources. The objective was to describe financial parameters of care for patients resuscitated from OOHCA.

METHODS

This was a retrospective review of OOHCA patients admitted to one academic teaching hospital from January 2004 to October 2007. Demographic data, length of stay (LOS), and discharge disposition were obtained for all patients. Financial parameters of patient care including total cost, net revenue, and operating margin were calculated by hospital cost accounting and reported as median and interquartile range (IQR). Groups were dichotomized by survival to discharge for subgroup analysis. To provide a reference group for context, similar financial data were obtained for ST-segment elevation myocardial infarction (STEMI) patients admitted during the same time period, reported with medians and IQRs.

RESULTS

During the study period, there were 72 admitted OOCHA patients and 404 STEMI patients. OOCHA and STEMI groups were similar for age, sex, and insurance type. Overall, 27 (38.6%) OOHCA patients survived to hospital discharge. Median LOS for OOHCA patients was 4 days (IQR = 1-8 days), with most of those hospitalized for <or=4 days (n = 34, 81.0% dying or discharged to hospice care). Median net revenue ($17,334 [IQR $7,015-$37,516] vs. $16,466 [IQR = $14,304-$23,678], p = 0.64) and operating margin ($7,019 [IQR = $1,875-$15,997] vs. $7,098 [IQR = $3,767-$11,138], p = 0.83) for all OOHCA patients were not different from STEMI patients. Net income for OOCHA patients was not different than for STEMI patients (-$322 vs. $114, p = 0.72).

CONCLUSIONS

Financial parameters for OOHCA patients are similar to those of STEMI patients. Financial issues should not be a negative incentive to providing care for these patients.

[Public access defibrillation. Limited use by trained first responders and laymen]

As ventricular fibrillation is the most frequent initial heart rhythm causing out-of-hospital sudden cardiac arrest, defibrillation is of essential significance. Automated external defibrillators (AEDs) have been available for some years and as a result defibrillation can be carried out by individuals other than physicians and healthcare providers such as trained first responders and untrained lay rescuers. This so-called public access defibrillation nourished hope of progress in the treatment of sudden cardiac arrest. However, several limitations exist, such as low frequency of sudden cardiac arrest in public, rare use of publicly placed AEDs, low cost effectiveness, legal requirements and insufficient public willingness to help. Due to these restrictions of public access defibrillation other measures are more promising than the attempt at general distribution of AEDs. These measures are primary or secondary prophylaxis of sudden cardiac arrest, general knowledge of adequate activation of emergency medical services, implementation of first responder teams equipped with AEDs and particularly a better education in and application of the well-established principles of cardiopulmonary resuscitation.

Economic value of out-of-hospital emergency care: a structured literature review

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.

Cost-effectiveness of Different Advanced Life Support Providers for Victims of Out-of-hospital Cardiac Arrests

BACKGROUND/PURPOSE

The survival rate of out-of-hospital cardiac arrest (OHCA) is only about 1.4% in Taiwan. The best configuration to achieve optimal outcomes in OHCA is still uncertain for many communities. The purpose of this study was to investigate the cost-effectiveness of two models of providing advanced life support (ALS) services, emergency medical technicians (EMTs) vs. emergency physicians (EPs), in a two-tiered emergency medical services (EMS) system.

METHODS

This was a prospective, observational, multicenter study comparing ALS provided by EMTs vs. EPs for the management of victims of OHCA. The study population consisted of patients experiencing OHCA of non-traumatic origin in Taipei city, Taiwan, between November 1999 and December 2000, for whom ALS was activated. We performed a cost-effectiveness analysis to determine the economic attractiveness of these two ALS provider programs. The outcome measurements were aggregate costs, survival and incremental cost per life saved. Sensitivity analyses were performed on all variables.

RESULTS

The expected total cost per OHCA patient was 2,248.19 US$ and 832.07 US$ for the EMT and EP programs, respectively. The overall survival rate was 4.4%. The survival rate was 9.3% for the EMT program and 2.6% for the EP program. The incremental cost-effectiveness ratio (ICER) of EMTs vs. EPs was 21,136 US$ per life saved. The ICER was sensitive to hospital admission cost changes and the probability of survival to discharge in patients admitted to hospital in the EMT program. The increased survival rate of OHCA patients in the EMT program may be attributable to the services of the hospital and/or the EMT program.

CONCLUSION

The use of EMTs as ALS care providers for OHCA patients in the two-tiered EMS system resulted in a reasonable cost-effectiveness ratio. EMTs could be considered as the second tier of EMS systems in urban areas in Taiwan.

Modeling an emergency medical services system using computer simulation

STUDY OBJECTIVES

In the emergency medical services (EMS) system, appropriate prehospital care can substantially decrease casualty mortality and morbidity. This study designed a simulation model, evaluated the existing EMS system, and suggested improvements.

METHODS

The study focused on 23 networked EMS hospitals affiliated with 36 emergency response units (subgroups) to perform two-tier rescues (advanced life support [ALS] in addition to basic life support [BLS] services) in Taipei, Taiwan. Using the existing EMS model as a base, this research constructed a computer simulation model and explored several model alternatives to achieve the study's objectives. The virtual models varied with staffing level, number of assigned emergency network hospitals, and various two-tier rescue probabilities.

RESULTS

Increasing the staffing to two teams for Hospital 22 lessened the call waiting probability (delay between rescue call and ambulance dispatch) by 50%, even if the dispatch rate of the two-tier rescue increased from the empirical 2% to a simulated 10 and 20%. Changing the two-tier rescue pattern so each EMS subgroup cooperated with two specific, preassigned network hospitals lowered the probability of patients having to wait for rescue dispatch to under 1%.

CONCLUSION

The following alternatives provided the greatest combination of effectiveness, quality patient care, and cost-efficiency: (1) because of its unique location, increase Hospital 22's staffing level to two ALS teams. (2) Establish a specific rescue protocol for the two-tier system that preassigns two network hospitals to each of the 36 EMS subgroups along with a prearranged calling sequence. If implemented, this will improve EMS performance, streamline the system, reduce randomness, and enhance efficiency.

Cost-effectiveness of helicopter transport of stroke patients for thrombolysis

OBJECTIVES

Treatment with intravenous (IV) or intra-arterial (IA) thrombolysis in patients with acute ischemic stroke demands careful patient selection and specialized institutional capabilities. Physicians at hospitals without these resources may prefer patient transfer for acute treatment. Helicopter transport for these patients has been described but without analysis of the effects of its additional cost. The authors examined the cost-effectiveness of helicopter transport for patients with acute stroke.

METHODS

Costs per additional good outcome and per quality-adjusted life-year (QALY) were calculated using a computer model. Input variables included flight, thrombolytic agent, and angiography costs; annual cost per patient for long-term care of symptomatic stroke; percentage of transported patients treated; percentage of patients receiving IV versus IA therapy; discount rate; absolute probability of good outcome; annual mortality with and without treatment; and quality-of-life modifier. Sensitivity analysis was performed.

RESULTS

Helicopter transport of acute stroke patients to tertiary care centers for thrombolytic therapy costs $35,000 per additional good outcome and $3,700 per QALY for the reference case. Cost-effectiveness was sensitive to the effectiveness of thrombolysis but minimally sensitive to most other input values. Cost per QALY ranged from $0 to $50,000, as the absolute increase in good outcomes (minimal or no deficit) ranged from 20% to 5%. Cost-effectiveness was not sensitive to ranges of helicopter flight costs or the proportion of flown patients undergoing treatment.

CONCLUSIONS

This model indicates helicopter transfer of patients with suspected acute ischemic stroke for potential thrombolysis is cost-effective for a wide range of system variables.

Emergency medical services and mortality from heart disease: a community study

STUDY OBJECTIVES

Little is known regarding the potential effects of emergency medical services (EMS) on total heart disease mortality. Although EMS may provide health benefits in less acute cardiac conditions, its immediate, measurable, and direct effect on heart disease mortality is through resuscitation of persons suffering out-of-hospital cardiac arrest. The purpose of this study was to examine the involvement and potential mortality benefit of out-of-hospital EMS care of cardiac arrest on community heart disease mortality.

METHODS

The investigation was an observational study of all persons with death events resulting from heart disease as defined by heart disease deaths and deaths averted (persons successfully resuscitated from out-of-hospital cardiac arrest by EMS) in a single county from January 1, 2000, through December 31, 2000. The county of study has a population of nearly 2 million people and is composed of urban, suburban, and rural components. State vital records and EMS reports were used to ascertain deaths resulting from heart disease and deaths averted.

RESULTS

In the year 2000, 3,577 persons died as a result of heart disease, and 128 persons were successfully resuscitated and discharged from the hospital, for a total of 3,705 death events. EMS responded to 39% (1,428/3,705) of all heart disease death events and 57% (1,428/2,516) of out-of-hospital events, resulting in a 3.5% (128/3,705) reduction in overall heart disease mortality and a 5.1% (128/2,516) reduction in out-of-hospital mortality.

CONCLUSION

EMS was involved in the majority of out-of-hospital heart disease death events, resulting in a measurable reduction in heart disease mortality.

EMS ... agenda for the future

In 1996, the National Highway Traffic Safety Administration and the Health Resources and Services Administration, Maternal and Child Health Bureau published the EMS Agenda for the Future. To date, thousands of copies have been distributed to EMS-knowledgeable people, and those who aspire to be, throughout the United States. This article reviews the findings discussed within the EMS Agenda for the Future. This discussion also assesses the effects of these findings on EMS development.

Prehospital ACLS--does it work?

Cardiac disease is the most common cause of death in the United States, and sudden cardiac arrest frequently claims the lives of men and women during their most productive years. It is believed that much better survival rates can be achieved for victims of cardiac arrest through optimizing the "chain of survival" as described by the American Heart Association. The relative and incremental benefit of full prehospital ACLS over basic life support and defibrillation is unproven, however. This is an important issue in this era of cost containment. Some of the ongoing studies including the OPALS study may clarify the cost effectiveness and relative efficacy of rapid defibrillation and full ACLS programs for victims of prehospital cardiac arrest [6].

Resource reallocation in an emergency medical service system using computer simulation

Emergency medical service (EMS) policy makers must seek to achieve maximum effectiveness with finite resources. This research establishes an EMS computer simulation model using eM-Plant software. The simulation model is based on Taipei city's EMS system with input data from prehospital care records from December 2000; it manipulates resource allocation levels and rates of idle errands. Presently, EMS ambulance utilization is about 8.78%. On average, 20.89 minutes are required to transport a patient to the hospital. Computer simulations showed that reducing the number of ambulances to one at each of the 36 response units increases the utilization rate to 15.47% but does not compromise the current service quality level. Thus, ambulance utilization improves, times of patients waiting for pre-hospital care and arrival at hospitals are only slightly affected, and considerable cost savings result. This study provides a research methodology and suggests specific policy directions for resource allocation in EMS. Limiting the number of ambulances to one per response unit reduces costs, increases efficiency, and yet maintains the same operational pattern of medical service.

Estimated cost effectiveness of a police automated external defibrillator program in a suburban community: 7 years experience

OBJECTIVE

To estimate the cost effectiveness of a 7-year police automatic external defibrillator (AED) program in four suburban communities.

METHOD

10-year retrospective study (7/89-7/99) of patients of four suburban communities during two study periods: (1) police first response and advanced life support (ALS) care (No-AED) and; (2) AED equipped police first response (P-AED) with subsequent ALS care. Using the perspective of the communities, we obtained costs of AED program from police agencies. We estimated cost/life saved and cost/year lives saved using decreased time to VF shock by EMS. We performed a sensitivity analysis for estimates of potential benefit using estimated improved survival as a result of decreased EMS response interval and obtained survival data. We used literature-based estimates of life expectancy after cardiac arrest survival to estimate cost/year life saved. We used student's t-test and chi(2) to estimate differences between groups.

RESULTS

During the 10-year study period 208 patients met study criteria; (81 No-AED, 128 P-AED). The two groups were not different by patient age, ALS response interval, percent in VF, percent witnessed (WIT), or arrest location. Interval to first defibrillator equipped EMS vehicle arrival was less in the P-AED group (2.0 vs. 5.4 min, P<0.001) as was the interval from the emergency (911) call to first VF shock (6.6 vs. 8.4 min, P=0.02). Survival to DC was not statistically different with P-AED (11.9 vs. 9.9%, P=0.66) but this study was not powered to detect a difference. Estimated cost per life saved with P-AED varied from $23542 to $70342 and cost per year life saved ranged from $1582 to $16060.

CONCLUSION

Police AED appears to be a cost-effective intervention in these suburban communities which have relatively rapid EMS response intervals.

Out of hospital cardiac arrests--the experience of one hospital in Singapore

In Singapore, all public emergency ambulances are equipped with semi-automatic external defibrillators and the crew is trained in their use. This is the first paper from Singapore reporting the survival rate in patients presenting to an urban public hospital with acute coronary syndrome (ACS) who developed out-of-hospital cardiac arrest (OHCA). All consecutive patients who presented to the ED of a public hospital with OHCA or ACS were surveyed from 1 April 1999 to 30 September 1999. There were 392 patients among whom 115 (28.5%) had OHCA. There was no significant difference in age and gender distribution between the OHCA and non-OHCA patients. More than 2/3 of the OHCA patients had no report of chest pain or breathlessness before they collapsed. Forty five (39.1%) of the 115 OHCA patients were noted to have initial rhythms of ventricular tachycardia (VT) or ventricular fibrillation (VF) and received pre-hospital defibrillation. The mean time from collapse to first DC shock was 12.07+/-7.2 min. Twenty (17.4%) of the OHCA patients had return of spontaneous circulation after resuscitation in the ED. Four patients (3.5%), all with an initial rhythm of VF were discharged alive from the hospital. Much remains to be done to reduce the time interval to first DC shock for the OHCA group.

Emergency Medical Services Outcomes Project (EMSOP) II: developing the foundation and conceptual models for out-of-hospital outcomes research

Development of methodologically acceptable outcomes models for emergency medical services (EMS) is long overdue. In this article, the Emergency Medical Services Outcomes Project proposes a conceptual framework that will provide a foundation for future EMS outcomes research. The "Episode of Care Model" and the "Out-of-Hospital Unit of Service Model" are presented. The Episode of Care Model is useful in conditions in which interventions and outcomes, especially survival and major physiologic dysfunction, are linked in a time-dependent manner. Conditions such as severe trauma, anaphylaxis, airway obstruction, respiratory arrest, and nontraumatic cardiac arrest are amenable to this methodology. The Out-of-Hospital Unit of Service Model is essentially a subunit of the Episode of Care Model. It is valuable for evaluating conditions that have minimal-to-moderate therapeutic time dependency. This model should be used when studying outcomes limited to the out-of-hospital interval. An example of this is pain management for injuries sustained in motor vehicle crashes. These models can be applied to a wide spectrum of conditions and interventions. With the scrutiny of health care expenditures ever increasing, the identification of clinical interventions that objectively improve patient outcome takes on growing importance. Therefore, the development, dissemination, and use of meaningful methodologies for EMS outcomes research is key to the future of EMS system development and maintenance.

Cost-effectiveness analysis of a rural/urban first-responder defibrillation program

OBJECTIVE

To analyze the cost-effectiveness of a proposed first-responder defibrillation program in a small rural area in comparison with a recently initiated first-responder program in an adjoining urban center in southwestern Ontario. The purpose of the analysis was to quantify the expected benefits of the proposed program to determine whether the costs are justified.

METHODS

This analysis was conducted on the city of Waterloo (population 80,000 over 25 square miles) and the adjoining rural township of Wellesley (population 8,000 over 105 square miles). The township has volunteer fire department first responders with basic life support (BLS), and basic life support/defibrillation (BLS-D) ambulances as the second tier; whereas the city's full-time fire department has recently adopted a first-responder defibrillation (BLS-D) program backed up by the same BLS-D ambulance service. The most relevant costs identified were the capital costs of the defibrillators, ancillary equipment, and biomedical service for preventive maintenance and routine nonwarranty work. Response intervals and percentage of patients found in ventricular fibrillation were projected and sensitivity analysis was applied.

RESULTS

The projected cost per life saved is $6,776 (C) in the urban area and $49,274 (C) in the rural area using an incremental save rate of 6%. Applying sensitivity analysis to the data, the save rate varied from 2% to 10%, resulting in a cost per life saved of $20,328 (C) and $4,066 (C), respectively, in the urban community. For the rural area, the cost per life saved ranged from $147,821 (C) (2%) to $29,564 (C) (10%). Even the worst-case save rate for the urban center [2%; $20,328 (C)] is significantly less than the best-case save rate [10%; $29,564 (C)] for the rural area.

CONCLUSIONS

The cost per life saved for a rural first-responder defibrillation program is significantly more expensive than one for an urban center. However, the cost per life saved is still economical compared with common treatments for other life-threatening illnesses.

The Ontario Prehospital Advanced Life Support (OPALS) study Part II: Rationale and methodology for trauma and respiratory distress patients. OPALS Study Group

The Ontario Prehospital Advanced Life Support (OPALS) Study represents the largest prehospital study yet conducted, worldwide. This study will involve more than 25,000 cardiac arrest, trauma, and critically ill patients over an 8-year period (1994-2002). The current article, Part II, describes in detail the rationale and methodology for major trauma and respiratory distress patients and for an economic evaluation of Advanced Life Support (ALS) programs in the OPALS Study. The OPALS Study, using a rigorous controlled methodology and a large sample size, should clearly indicate the benefit in trauma and respiratory distress patient survival and morbidity that results from the widespread introduction of prehospital ALS programs to communities of many different sizes. [Stiell IG, Wells GA, Spaite DW, Nichol G, O'Brien B, Munkley DP, Field BJ, Lyver MB, Luinstra LG, Dagnone E, Campeau T, Ward R, Anderson S, for the OPALS Study Group: The Ontario Prehospital Advanced Life Support (OPALS) Study Part II: Rationale and methodology for trauma and respiratory distress patients.

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

STUDY OBJECTIVES

This study was conducted to identify modifiable factors associated with survival for prehospital cardiac arrest in a large, multicenter EMS system with basic life support/defibrillation (BLS-D) level of care.

METHODS

This observational cohort study constitutes Phase I of the 3-phase Ontario Prehospital Advanced Life Support (OPALS) Study. Included were all adults who had cardiac arrest before EMS arrival in 21 urban/suburban communities that operate under the jurisdiction of 1 ambulance services branch, have 911 telephone service, and provide ambulance defibrillation but no prehospital advanced life support (ALS). Central dispatch and ambulance records were reviewed according to the Utstein guidelines. Associations between multiple patient and EMS factors and survival to discharge were assessed by univariate then stepwise logistic regression analyses.

RESULTS

From January 1, 1991, to January 31, 1995, 5,335 eligible patients were treated. Of these, 46.8% of cardiac arrests were witnessed by citizens, 14.5% received bystander CPR, 25.6% received CPR by fire or police, and 38.2% had an initial rhythm of ventricular fibrillation/ventricular tachycardia (VF/VT). The mean interval from call received to vehicle stopped was 6.7 minutes. Survival was 3.5% overall and 8.8% for VF/VT. Multivariate analysis found the following factors to be independently associated with survival (odds ratio with 95% confidence intervals): age.81 (. 73,.89), bystander-witnessed arrest 4.05 (2.78, 5.90), bystander CPR 2.98 (2.07, 4.29), CPR by fire or police 2.20 (1.46, 3.31), and response interval call received to vehicle stopped.76 (.71,.82).

CONCLUSION

This represents the largest multicenter BLS-D study of prehospital cardiac arrest yet conducted and clearly indicates that patient survival may be improved by optimization of EMS response intervals, bystander CPR, as well as first-responder CPR by fire or police.

Response interval comparison between urban fire departments and ambulance services

OBJECTIVE

To measure the response intervals of fire departments compared with ambulance services in three urban centers to determine whether defibrillators should be added to fire vehicles.

METHODS

A prospective sample of 1,882 code 4 (life-threatening) tiered calls were collected over a six-month period from March 1, 1994, to August 31, 1994. A matched pairs experimental design compared the response interval of the fire department with that of the ambulance service for each call. This emergency medical services (EMS) system encompasses three urban centers with populations of 80,000, 95,000, and 170,000.

RESULTS

In two of three of the urban centers, the fire department arrived on scene more than a minute sooner than the ambulance service: Cambridge (n = 571, mean = 2.22 min, p < 0.0001); Kitchener (n = 1,011, mean = 1.24 min, p < 0.003); and Waterloo (n = 300, mean = 0.69 min, p < 0.98).

CONCLUSIONS

The shorter response interval of fire departments suggests placing defibrillators on fire response vehicles in an effort to decrease the time to defibrillation for cardiac arrest victims in this EMS system.

Out-of-hospital treatment of hypoglycemia: refusal of transport and patient outcome

OBJECTIVES

Patient refusal of transport after treatment of hypoglycemia is common in urban emergency medical services (EMS) systems. The rate of relapse is unknown. The goal of this study was to compare the outcomes of diabetic patients initially refusing transport (refusers) and those transported to an ED.

METHODS

All paramedic runs from January to July 1995 were retrospectively reviewed. Inclusion criteria were adult patients with a field assessment of hypoglycemic signs/symptoms, and a fingerstick glucose <80 mg/dL. Data for analysis included paramedic run duration, patient demographics, and refusal or acceptance of transport. Patient outcome was obtained from a review of hospital and medical examiner records. Relapse was defined as hypoglycemia necessitating EMS activation or an ED visit within 48 hours of the initial episode. Student's t-test and chi2 analysis were used to compare means and rates, respectively.

RESULTS

Over the 7 months, 374 patients made 571 calls to 9-1-1 that met inclusion criteria (5.2% of all paramedic runs). Of these, 412 were refusers (72.2%) and 159 were transported patients (27.8%). The hospital records of 4 transported patients were unavailable. Sixty-three transported patients were admitted (11.2%), with 1 death from prolonged hypoglycemia. The rates of relapse did not differ between the refusers and the transported patients (p > 0.05). Twenty-five relapses occurred among the refusers (6.1%), with 14 repeat refusals, 11 transports, 5 admissions, and no deaths. There were 7 relapses among the transported patients (4.4%), with 2 refusals, 5 transports, 2 admissions, and no deaths. The paramedic run time was significantly shorter for the refusers than for the transported patients (p < 0.05).

CONCLUSIONS

The out-of-hospital treatment of hypoglycemic diabetic patients appears to be effective and efficient. Independent of the patient's refusal or acceptance of transport, the out-of-hospital treatment of hypoglycemic patients in this system appears to be safe.

The Ontario Prehospital Advanced Life Support (OPALS) Study: rationale and methodology for cardiac arrest patients

The Ontario Prehospital Advanced Life Support Study represents the largest prehospital study yet conducted, worldwide. This study will involve more than 25,000 cardiac arrest, trauma, and critically ill patients over an 8-year period. The study will evaluate the incremental benefit of rapid defibrillation and prehospital Advanced Cardiac Life Support measures for cardiac arrest survival and the benefit of Advanced Life Support for patients with traumatic injuries and other critically ill prehospital patients. This article describes the OPALS study with regard to the rationale and methodology for cardiac arrest patients.

EMS Agenda for the Future: where we are...where we want to be

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the EMS Agenda for the Future. Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are integration of health services, EMS research, legislation and regulation, system finance, human resources, medical direction, education systems, public education, prevention, public access, communication systems, clinical care, information systems, and evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.

Developing a foundation for the evaluation of expanded-scope EMS: a window of opportunity that cannot be ignored

EMS systems are about to undergo a major transformation. Not only will the scope of EMS change, but many experts believe that it will dramatically expand. Some see the "expanded scope" as entailing relatively limited changes, whereas others consider them to be more broad. Although no agreement is evident about the definition for expanded-scope EMS, it is hoped that all EMS professionals can agree that it must be implemented in a manner that can be carefully evaluated to determine its effects on patients and EMS systems. We present a framework for evaluating the effect of expanded-scope EMS in the various types of systems that currently exist. Special consideration must be given to the indirect effects that system changes may have on survival from out-of-hospital cardiac arrest. Numerous issues will affect our ability to properly assess expanded-scope EMS. The basic research models necessary to assess the impact of system change are lacking. Few EMS systems consistently produce significant volumes of good systems research ... that is, there are few "EMS laboratories." Cost-effectiveness and issues surrounding the "societal value" of EMS remain essentially unstudied. Reliable scoring methods, severity scales, and outcome measures are lacking: and, it is ethically and logistically difficult to justify withholding the "standard of care" in an effort to understand the impact of EMS interventions. Despite all of these barriers, it is time to pay the price of doing methodologically sound evaluations that ensure the most optimal societal impact by the EMS systems of the future.

Cost-effectiveness analysis of helicopter EMS for trauma patients

STUDY OBJECTIVE

To evaluate the cost-effectiveness of helicopter EMS for trauma patients.

METHODS

We applied a cost-effectiveness analysis from the service provider's perspective to cost and effectiveness estimates. The cost estimates comprise direct operating costs and additional survivors' hospital costs. The effectiveness estimates were calculated with the TRISS methodology from literature sources and data from a cohort of patients transported by helicopter during 1994 and 1995. Sensitivity analysis and discounting were used. Cost per life saved and discounted cost per year of life in 1995 US dollars were the main outcome measures.

RESULTS

The reported literature survival benefit ranges from 1 to 12 additional survivors per 100 patients flown. Transport costs were $2,214 per patient, and each additional survivor's hospitalization averaged $15,883. For the base case (5 additional survivors per 100 patients flown), cost per life was $60,163 and discounted cost per year of life $2,454. Sensitivity analysis revealed that discounted cost per year of life could be as high as $9,677 or as low as $1,400 and that it was most dependent on the surviving benefit. These results are comparable to a reported median discounted cost per year of life of %19,000 for other commonly used lifesaving medical interventions.

CONCLUSION

Assuming that helicopter air medical transport provides a substantial survival benefit for trauma patients, our findings suggest that this service is a cost-effective option for the treatment of trauma patients. The magnitude of the survival benefit is the most important factor determining cost-effectiveness.

Paramedics, technicians, and survival from out of hospital cardiac arrest

OBJECTIVE

To test the hypothesis that limited paramedic advanced life support skills afford no advantage in survival from cardiac arrest when compared with non-paramedic ambulance crews equipped with defibrillators in an urban environment; and to investigate whether separate response units delayed on scene times.

METHODS

A prospective, observational study was conducted over 17 consecutive months on all adult patients brought to the accident and emergency (A&E) department of Glasgow Royal Infirmary having suffered an out of hospital cardiac arrest of cardiac aetiology. The main interventions were bystander cardiopulmonary resuscitation (CPR) and limited advance life support skills.

MAIN OUTCOME MEASURES

Return of spontaneous circulation, survival to admission, and discharge.

RESULTS

Of 240 patients brought to the A&E department, 19 had no clear record of whether a paramedic was or was not involved and so were excluded. There was no difference in survival between the two groups, although a trend to admission favoured non-paramedics. Paramedics spent much longer at the scene (P < 0.0001). Witnessed arrests (P = 0.01), early bystander CPR (P = 0.12), shockable rhythms (P = 0.003), and defibrillation (P < 0.0001) were associated with better survival. Intubation and at scene times were not associated with better survival. Delayed second response units did not prolong at scene times.

CONCLUSIONS

The interventions of greatest benefit in out of hospital cardiac arrest are basic life support and defibrillation. Additional skills are of questionable benefit and may detract from those of greatest benefit.

Cardiopulmonary resuscitation: what cost to cheat death?

OBJECTIVES

To review the various outcomes from cardiopulmonary resuscitation (CPR), the factors that influence these outcomes, the costs associated with CPR, and the application of cost-analyses to CPR.

DATA SOURCES

Data used to prepare this article were drawn from published articles and work in progress.

STUDY SELECTION

Articles were selected for their relevance to the subjects of CPR and cost-analysis by MEDLINE keyword search.

DATA EXTRACTION

The authors extracted all applicable data from the English literature.

DATA SYNTHESIS

Cost-analysis studies of CPR programs are limited by the high variation in resources consumed and attribution of cost to these resources. Furthermore, cost projections have not been adjusted to reflect patient-dependent variation in outcome. Variation in the patient's underlying condition, presenting cardiac rhythm, time to provision of definitive CPR, and effective perfusion all influence final outcome and, consequently, influence the cost-effectiveness of CPR programs. Based on cost data from previous studies, preliminary estimates of the cost-effectiveness of CPR programs for all 6-month survivors of a large international multicenter collaborative trial are $406,605.00 per life saved (range $344,314.00 to $966,759.00), and $225,892.00 per quality-adjusted-life-year (range $191,286.00 to $537,088.00).

CONCLUSIONS

Reported outcome from CPR has varied from reasonable rates of good recovery, including return to full employment to 100% mortality. Appropriate CPR is encouraged, but continued widespread application appears extremely expensive.

Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest

STUDY OBJECTIVE

To measure the incremental cost-effectiveness of various improvements to emergency medical services (EMS) systems aimed at increasing survival after out-of-hospital cardiac arrest.

METHODS

We performed cost-effectiveness analysis based on (1) metaanalysis of effectiveness of the various EMS systems, (2) costing of each component of EMS systems, (3) modeling of the relationship between the proportion of cardiac arrest victims who receive CPR and the proportion of individuals trained, (4) modeling of the relationship between response time interval and the characteristics of the EMS system, (5) measurement of quality of life, and (6) decision analysis to combine the results of the first five components.

RESULTS

The incremental cost-effectiveness ratio for a 48-second improvement in mean response time in a one-tier EMS system yielded by the addition of more EMS providers was $368,000 per quality-adjusted life year (QALY). For improved response time in a two-tier EMS system by the addition of more basic life support (BLS)/BLS-defibrillator (BLS-D) providers to the first tier, the ratio was $53,000 per QALY with pump vehicles or $159,000 per QALY with ambulances. Change from a one-tier EMS to a two-tier EMS system by the addition of initial BLS/BLS-D providers in pump vehicles as the first tier was associated with a cost per QALY of $40,000. Change from one-tier EMS to two-tier EMS by the addition of initial BLS/BLS-D providers in ambulances as the first tier was associated with a cost per QALY of $94,000.

CONCLUSION

The most attractive options in terms of incremental cost-effectiveness were improved response time in a two-tier EMS system or change from a one-tier to a two-tier EMS system. Future research should be directed toward identification of the costs of instituting the first tier of a two-tier EMS system and identification of cost-effective methods of improving response time.

Comparison of ambulance dispatch protocols for nontraumatic abdominal pain

STUDY OBJECTIVE

To compare rates of undertriage and overtriage of six ambulance dispatch protocols for the presenting complaint of nontraumatic abdominal pain, and to identify the optimal protocol.

DESIGN

Retrospective prehospital and emergency department chart review to classify patients' conditions as "emergency" or "nonemergency." Utility analysis was used to identify the preferred protocol and monetary cost-effectiveness analysis to identify the least expensive protocol.

SETTING

County emergency medical services (EMS) system with five receiving hospitals serving a mainly urban population of approximately 350,000.

PARTICIPANTS

Records of 902 patients who called 911 for nontraumatic abdominal pain were reviewed; patients not transported were excluded. Twenty-seven county EMS medical directors completed questionnaires.

RESULTS

Six ambulance dispatch protocols for nontraumatic abdominal pain were developed: indiscriminate-dispatch, four selective protocols, and no-dispatch. A dichotomous classification system was derived prospectively from the prehospital and medical records of patients who had activated the EMS system before the study period to define "emergency" and "nonemergency" conditions associated with nontraumatic abdominal pain. Emergency criteria identified patients with conditions requiring medical treatment within 1 hour. Reviewers determined, for each patient, whether an ambulance would have been dispatched by each of the protocols. Undertriage and overtriage rates were calculated for each protocol. County EMS medical directors assigned utility values to four potential outcomes of ambulance dispatch by the direct scaling method. The outcomes comprised correct and incorrect decisions to dispatch ambulances to patients with and without emergencies. The protocols were compared by decision analysis. A cost analysis was also performed, using an estimated marginal cost per transport of $302. Sensitivity analysis demonstrated the effect of varying the cost of an undertriage error and the cost per response. Of the 788 patients included in the study, 7.8% had conditions defined as emergencies. The four selective ambulance dispatch protocols had overtriage rates ranging from 10% to 51% and undertriage rates of 4% to 7%. None of the protocols was proven superior on the basis of the medical directors' assignment of utility values. The marginal cost of dispatching advanced life support ambulances to all patients with this complaint was $3,838 per emergency.

CONCLUSION

The majority of patients with nontraumatic abdominal pain who requested ambulance transport during the study period did not have conditions that were classified as emergencies. In the study model, if an undertriage error costs more than $3,674, indiscriminate ambulance dispatch is the least expensive protocol, and if an undertriage error costs less than $3,674, no ambulance dispatch is the least expensive strategy.

Emergency medical service systems research: problems of the past, challenges of the future

Out-of-hospital emergency care was designed around the concept of a system of interrelated events that combine to offer a patient the best care possible outside the hospital. However, in contrast to the actual operations of emergency medical service (EMS) systems, research has not typically used systems-based models as the method for evaluation. In this discussion we outline the weaknesses of component-based research models in EMS evaluation and attempt to provide a "systems-analysis" framework that can be used for future research. Incorporation of this multidiscipline approach into EMS research is essential if there is to be any hope of finding answers to many of the important questions that remain in the arena of out-of-hospital health care.

Out-of-hospital cardiac arrest: two and a half years experience of an accident and emergency department in Hong Kong

The results are presented of 2 1/2 years of experience of patients with out-of-hospital cardiac arrests who were resuscitated in an accident and emergency department (A&E) attached to an acute district hospital in Hong Kong. Out of 263 cases of out-of-hospital cardiac arrest as a result of a variety of causes only seven patients survived (3%) and among the 135 patients with cardiac aetiology only four survived (3%). Ways to improve the outcome for out-of-hospital cardiac arrest are discussed.

Prospective validation of a new model for evaluating emergency medical services systems by in-field observation of specific time intervals in prehospital care

STUDY OBJECTIVE

To develop and validate a new time interval model for evaluating operational and patient care issues in emergency medical service (EMS) systems. DESIGN/SETTING/TYPE OF PARTICIPANT: Prospective analysis of 300 EMS responses among 20 advanced life support agencies throughout an entire state by direct, in-field observation.

RESULTS

Mean times (minutes) were response, 6.8; patient access, 1.0; initial assessment, 3.3; scene treatment, 4.4; patient removal, 5.5; transport, 11.7; delivery, 3.5; and recovery, 22.9. The largest component of the on-scene interval was patient removal. Scene treatment accounted for only 31.0% of the on-scene interval, whereas accessing and removing patients took nearly half of the on-scene interval (45.8%). Operational problems (eg, communications, equipment, uncooperative patient) increased patient removal (6.4 versus 4.5; P = .004), recovery (25.4 versus 20.2; P = .03), and out-of-service (43.0 versus 30.1; P = .007) intervals. Rural agencies had longer response (9.9 versus 6.4; P = .014), transport (21.9 versus 10.3; P < .0005), and recovery (29.8 versus 22.1; P = .049) interval than nonrural. The total on-scene interval was longer if an IV line was attempted at the scene (17.2 versus 12.2; P < .0001). This reflected an increase in scene treatment (9.2 versus 2.8; P < .0001), while patient access and patient removal remained unchanged. However, the time spent attempting IV lines at the scene accounted for only a small part of scene treatment (1.3 minutes; 14.1%) and an even smaller portion of the overall on-scene interval (7.6%). Most of the increase in scene treatment was accounted for by other activities than the IV line attempts.

CONCLUSION

A new model reported and studied prospectively is useful as an evaluative research tool for EMS systems and is broadly applicable to many settings in a demographically diverse state. This model can provide accurate information to system researchers, medical directors, and administrators for altering and improving EMS systems.

Beyond Utstein: implementation of a multisource uniform data base for prehospital cardiac arrest research

This article is an overview of the issues affecting the use of a multisource uniform data base for prehospital cardiac arrest research. The goals of data base standardization include improved communication between emergency medical services (EMS) systems and between EMS physicians and the lay public; improved quantification of EMS system performance and documentation of benefit; in-depth analysis of factors that contribute to outcome; and development of EMS system models that will enhance system planning. Challenges to developing a multisource research data base include establishing a concensus approach to data base development; enlisting EMS system cooperation; verifying the accuracy of the data collected; coordinating data storage and analysis; and obtaining fiscal support for such a project. One illustrative approach to initiating multisource data base research is outlined. The iterative nature of data base development, use, expansion, and refinement is emphasized. Future reports addressing the methodology of multisource data base development and application in EMS systems should build on these concepts.

Do-not-resuscitate orders. Where are they in the prehospital setting?

Without a well-functioning, prehospital, do-not-resuscitate (DNR) system in place, emergency medical service (EMS) providers must resuscitate all patients who access the system, regardless of the patients' wishes and regardless of what makes ethical or economic sense. In lieu of valid documentation, it is not appropriate to withhold resuscitative measures in this critical, time-dependent situation. In order to help EMS systems implement functional prehospital DNR protocols, this paper reviews the state-of-the-art of prehospital DNR including the issues to consider when designing such a system and a discussion of the features of some of the existing systems. This review includes: 1) the basis and requirements of a DNR system; 2) legal and physical forms for DNR orders; 3) eligibility for DNR status; 4) reversal of DNR orders; and 5) inappropriate use of EMS systems for DNR patients. Finally, a more general discussion of overall resource utilization in prehospital resuscitations is presented to emphasize that implementing prehospital DNR systems is only one piece of a larger issue.