Factors associated with CPR certification within an elderly community.

OBJECTIVE: To determine the frequency of CPR certification amongst residents living within a predominantly elderly community and examine the perceived barriers to learning basic CPR and factors associated with intent to become certified. METHODS: A household survey was sent with a community newsletter to each home of a non-gated elderly community that requires one member of each household to be at least 55 years of age. The community consists of 2488 homes (approximately 4000 residents). Thirteen Yes/No questions were asked in a skip-pattern based upon the question: "Are you CPR certified?" Data analysis included univariate, bivariate, and logistic regression. RESULTS: 947 participants with a mean age of 69 completed and returned the survey. Forty-eight percent of the participants had received prior training in CPR. Eighty-four percent were not currently certified in CPR, and top reasons cited were: 'don't know why' (36%), 'lack of interest' (20%), 'concerned about health risks' (17%). Forty-six percent of those not certified desired certification. Increasing age was inversely associated with CPR certification status and the desire to be certified. CONCLUSION: Almost half of the residents in this predominantly elderly community had received prior training in CPR, although most were not currently certified and cite significant specific and non-specific reasons and obstacles. Improved survival requires targeted interventions to achieve higher proportions of CPR-competent individuals in such high-risk communities.

Improving emergency medical services for children with special health care needs: does training make a difference?

This study evaluated the impact of a paramedic training program on emergency medical services (EMS) responses for children with special health care needs. EMS responses for children with a congenital or acquired condition or a chronic physical or mental illness, were reviewed. Responses, related to the child's special health care need, involving paramedics who had completed our training program were compared with responses with paramedics not participating in the training. There was significantly more advanced life support treatment for responses with paramedics completing the training program compared with other responses. However, there was no significant difference in transport to a hospital or in-hospital admission between these 2 groups. This finding suggests that existing EMS protocols may play a more important role in emergency treatment and transport of children with special health care needs than specialized training of already certified paramedics.

Emergency medical services assessment and treatment of children with special health care needs before and after specialized paramedic training.

INTRODUCTION: This study evaluates whether a continuing education program for paramedics, focusing on Children with Special Health Care Needs, improved paramedics' assessment and management. METHODS: Emergency Medical Services responses for children, 21 years of age or younger, with a congenital or acquired condition or a chronic physical or mental illness, were identified. The responses before and after the specialized education program were reviewed by a multidisciplinary team to evaluate assessment and management of the children. Interreviewer agreement between the nurses on the team and between the physicians on the team was assessed. We also evaluated whether there was an improvement in assessment and care by paramedics completing our education program. RESULTS: Significant improvement was seen in appropriate assessment and overall care by paramedics who completed our specialized education program. Reviewers also noted an appropriate rating for the initial assessment category more often for responses involving paramedics who had the training. Agreement on whether assessment and treatment was appropriate for all five reviewers varied considerably, ranging from 32% to 93%. Overall there was a high percentage of agreement (>70%) between the nurses and between the physicians on most items. However, kappa statistics did not generally reflect good agreement except for most of the focused assessment items and some treatment and procedure items. CONCLUSION: Most of the documentation on the EMS records indicated appropriate assessment and treatment during all responses for Children with Special Health Care Needs. Nevertheless, the results indicate that paramedics may improve their assessment and management of these children after specialized continuing education.

CPR-only survivors of out-of-hospital cardiac arrest: implications for out-of-hospital care and cardiac arrest research methodology.

STUDY OBJECTIVE: There is little evidence that cardiopulmonary resuscitation (CPR) alone may lead to the resuscitation of cardiac arrest victims with other than respiratory causes (eg, pediatric arrest, drowning, drug overdose). The objective of this study was to identify out-of-hospital cardiac arrest survivors resuscitated without defibrillation or advanced cardiac life support. METHODS: This observational cohort included all adult survivors of out-of-hospital cardiac arrest of a cardiac cause from phases I and II of the Ontario Prehospital Advanced Life Support Study. During the study period, the system provided a basic life support/defibrillation level of care but no advanced life support. CPR-only patients were patients determined to be without vital signs by EMS personnel who regained a palpable pulse in the field with precordial thump or CPR only and then were admitted alive to the hospital. Six members of a 7-member expert review panel had to rate the patient as either probably or definitely having an out-of-hospital cardiac arrest, and a rhythm strip consistent with a cardiac arrest rhythm had to be present to be considered a patient. Criteria considered were witness status, citizen or first responder CPR, CPR duration, arrest rhythm and rate, and performance of precordial thump. RESULTS: From January 1, 1991, to June 30, 1997, 9,667 patients with out-of-hospital cardiac arrest were treated. The overall survival rate to hospital discharge was 4.6%. There were 97 apparent CPR-only patients admitted to the hospital. Application of the inclusion criteria yielded 24 CPR-only patients who had true out-of-hospital cardiac arrest and 73 patients judged not to have cardiac arrest. Of the 24 true CPR-only patients admitted to the hospital, 15 patients were discharged alive, 10 patients were witnessed by bystanders, and 7 patients were witnessed by EMS personnel. The initial arrest rhythm was pulseless electrical activity in 9 patients, asystole in 12 patients, and ventricular tachycardia in 3 patients. One patient with ventricular tachycardia converted to sinus tachycardia with a single precordial thump. CONCLUSION: CPR-only survivors of true out-of-hospital cardiac arrest do exist; some victims of out-of-hospital cardiac arrest of primary cardiac cause can survive after provision of out-of-hospital basic life support care only. However, many patients found to be pulseless by means of out-of-hospital evaluation likely did not have a true cardiac arrest. This has implications for the survival rates of most, if not all, previous cardiac arrest reports. Survival rates from cardiac arrest may actually be lower if one excludes survivors who never had a true arrest. The absence of vital signs by out-of-hospital assessment alone is not adequate to include patients in research reports or quality evaluations for cardiac arrest.

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.

Increasing paramedics' comfort and knowledge about children with special health care needs.

This study evaluated a continuing education program for paramedics about children with special health care needs (CSHCN). Pretraining, posttraining, and follow-up surveys containing two scales (comfort with CSHCN management skills and comfort with Pediatric Advanced Life Support [PALS] skills) were administered. Objective measures of knowledge were obtained from pre- and posttraining tests. Differences in average scores were assessed using t-tests. Response rates for paramedics completing the program ranged from 94% for the posttraining survey, 81% for the initial comfort survey, 56% for the knowledge pretest, and 56% for the follow-up survey. PALS comfort scores were significantly higher than CSHCN comfort scores both before and after training, both P < .01. Posttraining surveys showed an increase in CSHCN comfort, P < .01. The follow-up surveys showed a significant decline in CSHCN comfort, P = .05. Scores on the tests showed a similar pattern, with a significant increase in knowledge from pre- to posttraining (P = .02) and a significant decrease in knowledge from posttraining to follow-up (P < .01). Comfort was significantly higher for standard pediatric skills than for specialized management skills. Completion of the self-study program was associated with an increase in comfort and knowledge, but there was some decay over time.

Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos.

BACKGROUND: The use of automated external defibrillators by persons other than paramedics and emergency medical technicians is advocated by the American Heart Association and other organizations. However, there are few data on the outcomes when the devices are used by nonmedical personnel for out-of-hospital cardiac arrest. METHODS: We studied a prospective series of cases of sudden cardiac arrest in casinos. Casino security officers were instructed in the use of automated external defibrillators. The locations where the defibrillators were stored in the casinos were chosen to make possible a target interval of three minutes or less from collapse to the first defibrillation. Our protocol called for a defibrillation first (if feasible), followed by manual cardiopulmonary resuscitation. The primary outcome was survival to discharge from the hospital. RESULTS: Automated external defibrillators were used, 105 patients whose initial cardiac rhythm was ventricular fibrillation. Fifty-six of the patients 153 percent) survived to discharge from the hospital. Among the 90 patients whose collapse was witnessed (86 percent), the clinically relevant time intervals were a mean (+/-SD) of 3.5+/-2.9 minutes from collapse to attachment of the defibrillator, 4.4+/-2.9 minutes from collapse to the delivery of the first defibrillation shock, and 9.8+/-4.3 minutes from collapse to The arrival of the paramedics. The survival rate was 74 percent for those who received their first defibrillation no later than three minutes after a witnessed collapse and 49 percent for those who received their first defibrillation after more than three minutes. CONCLUSIONS: Rapid defibrillation by nonmedical personnel using an automated external defibrillator can improve survival after out-of-hospital cardiac arrest due to ventricular fibrillation. Intervals of no more than three minutes from collapse to defibrillation are necessary to achieve the highest survival rates.

Training paramedics: emergency care for children with special health care needs.

OBJECTIVE: To enhance knowledge and comfort related to the emergency care of children with special health care needs (CSHCN) through an innovative continuing education program for paramedics. METHODS: A self-study program presenting in-depth information about common problems that affect the assessment and management of a child's airway, breathing, circulation, disability, and environment (ABCDEs), regardless of the child's diagnosis, was developed. This program used a manual, a video, practice mannequins, and skills evaluations to teach skills to paramedics employed at a municipal fire department. RESULTS: Pre- and posttraining surveys found that the paramedics were significantly more comfortable with the assessment and management of CSHCN after the completion of the self-study program, with a pretraining average of 2.83 and posttraining average of 4.20 on a five-point Likert-type scale, t(37) = 12.87, p < 0.001. A skills evaluation showed that skills performance varied widely across 21 skills, ranging from skills mastery to low skills knowledge. On the posttraining survey, between 74% and 94% of the paramedics rated each topic (tracheostomies, indwelling central venous catheters, cerebrospinal fluid shunts, gastrostomies, child abuse, and latex allergy) as applicable to their practices as paramedics. CONCLUSION: Given the growing population of CSHCN, it is important to provide specialized education to increase an EMS provider's preparedness to respond to emergency situations involving children with special health care needs.

Cardiac arrest witnessed by emergency medical services personnel: descriptive epidemiology, prodromal symptoms, and predictors of survival. OPALS study group.

STUDY OBJECTIVE: The Utstein guidelines recommend that emergency medical services (EMS)-witnessed cardiac arrests be considered separately from other out-of-hospital cardiac arrest cases. The objective of this study was to assess EMS-witnessed cardiac arrest and to determine predictors of survival in this group. METHODS: This prospective cohort included all adults with an EMS-witnessed cardiac arrest in the 21 communities of the Ontario Prehospital Advanced Life Support (OPALS) study. Systems provided a basic life support with defibrillation (BLS-D) level of care. Case and survival definitions followed the Utstein style. Descriptive and univariate methods (chi(2) and t test) were used to characterize EMS-witnessed cardiac arrest. Multivariate logistic regression was undertaken to assess predictors of survival to hospital discharge. RESULTS: From January 1, 1991, to December 31, 1996, there were 9,072 cardiac arrest cases in the study communities. Of these, 610 (6.7%) were EMS-witnessed. The majority had preexisting cardiac or respiratory disease (81.5%) and experienced prodromal symptoms before EMS personnel arrived (91.4%). An initial rhythm of pulseless electrical activity was present in 50.1% of the patients, ventricular fibrillation/ventricular tachycardia in 34.2%, and asystole in 15.7%. Survival to discharge was 12.6%. Multivariate analysis identified the following as independent predictors of survival (odds ratio with 95% confidence intervals [CIs]): nitroglycerin use before EMS arrival: 2.3 (95% CI 1.2 to 4.5), prodromal symptoms of chest pain: 2.5 (95% CI 1.4 to 4.5) or dyspnea: 0.5 (95% CI 0.3 to 1.0), and unconsciousness on EMS arrival: 0.5 (95% CI 0.2 to 0.9). Patients with chest pain were more likely than dyspneic patients to experience ventricular fibrillation/ventricular tachycardia (62% versus 17%, P<.0001), and were 5 times more likely to survive (30.6% versus 6.3%, P<.0001). CONCLUSION: EMS-witnessed cases are clearly an important subset of out-of-hospital cardiac arrest and are characterized by 2 distinct symptom groups: chest pain and dyspnea. These symptoms are important predictors of survival and may also help determine underlying mechanisms before patient collapse. A later phase of the OPALS study will prospectively evaluate the impact of out-of-hospital advanced life support on the survival of victims of EMS-witnessed cardiac arrest.

Use of emergency medical services by children with special health care needs.

OBJECTIVE: This study describes emergency medical services (EMS) responses for children with special health care needs (CSHCN) in an urban area over a one-year period. METHODS: A prospective surveillance system was established to identify EMS responses for children, 21 years of age or younger, with a congenital or acquired condition or a chronic physical or mental illness. Responses related to the special health care needs of the child were compared with unrelated responses. RESULTS: During a one-year period, 924 responses were identified. Fewer than half of the responses were related to the child's special health care need. Younger children were significantly more likely to have a response related to their special needs than older children. Among related responses, seizure disorder was the most common diagnosis, while asthma was more common for unrelated responses. Almost 58% of the responses resulted in transport of the child to a hospital. CONCLUSIONS: Emergency medical services responses related to a child's special health care needs differ from unrelated responses. The most common special health care needs of children did not require treatment beyond the prehospital care provider's usual standard of care. These results are relevant for communities providing EMS services for CSHCN.

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.

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.

CONTEXT: Survival rates for out-of-hospital cardiac arrest are low; published survival rates in Ontario are only 2.5%. This study represents phase II of the Ontario Prehospital Advanced Life Support (OPALS) study, which is designed to systematically evaluate the effectiveness and efficiency of various prehospital interventions for patients with cardiac arrest, trauma, and critical illnesses. OBJECTIVE: To assess the impact on out-of-hospital cardiac arrest survival of the implementation of a rapid defibrillation program in a large multicenter emergency medical services (EMS) system with existing basic life support and defibrillation (BLS-D) level of care. DESIGN: Controlled clinical trial comparing survival for 36 months before (phase I) and 12 months after (phase II) system optimization. SETTING: Nineteen urban and suburban Ontario communities (populations ranging from 16 000 to 750 000 [total, 2.7 million]). PATIENTS: All patients who had out-of-hospital cardiac arrest in the study communities for whom resuscitation was attempted by emergency responders. INTERVENTIONS: Study communities optimized their EMS systems to achieve the target response interval from when a call was received until a vehicle stopped with a defibrillator of 8 minutes or less for 90% of cardiac arrest cases. Working both locally and provincially, communities implemented multiple measures, including defibrillation by firefighters, base paging, tiered response agreements with fire departments, continuous quality improvement for response intervals, and province-wide revision and implementation of standard dispatch policies. All response times were obtained from a central dispatch system. MAIN OUTCOME MEASURE: Survival to hospital discharge. RESULTS: The 4690 cardiac arrest patients studied in phase I and the 1641 in phase II were similar for all clinical and demographic characteristics, including age, sex, witnessed status, rhythm, and receipt of bystander cardiopulmonary resuscitation. The proportion of cases meeting the 8-minute response criterion improved (76.7% vs 92.5%; P<.001) as did most median response intervals. Overall survival to hospital discharge for all rhythm groups combined improved from 3.9% to 5.2 % (P = .03). The 33% relative increase in survival represents an additional 21 lives saved each year in the study communities (approximately 1 life per 120000 residents). The charges were estimated to be US $46900 per life saved for establishing the rapid defibrillation program and US $2400 per life saved annually for maintaining the program. CONCLUSION: An inexpensive, multifaceted system optimization approach to rapid defibrillation can lead to significant improvements in survival after cardiac arrest in a large BLS-D EMS system.

Emergency medical services outcomes project I (EMSOP I): prioritizing conditions for outcomes research.

Over the past several years, out-of-hospital EMS have come under increased scrutiny regarding the value of the range of EMS as currently provided. We used frequency data and expert opinion to rank-order EMS conditions for children and adults based on their potential value for the study of effectiveness of EMS care. Relief of discomfort was the outcome parameter EMS professionals identified as having the most potential impact for the majority of children and adults in the top quartile conditions. Future work from this project will identify appropriate severity and outcome measures that can be used to study these priority conditions. The results from the first year of this project will assist those interested in EMS outcomes research to focus their efforts. Furthermore, the results suggest that nonmortality out-come measures, such as relief of discomfort, may be important parameters in determining EMS effectiveness.

Development of an electronic emergency medical services patient care record.

OBJECTIVE: The need for valid and reliable emergency medical services (EMS) data has long been recognized. EMS data are useful for monitoring resources and operations, documenting patient care and outcome, and evaluating injury prevention strategies. The goal of this project was to develop a computerized data set with the capability to generate a patient care record (PCR) to overcome some of the current EMS data limitations. METHODS: The authors discuss developing an electronic PCR and analysis data set containing 233 variables. Data are collected for the following: incident, response, scene, patient, history, primary survey (including vital signs), physical examination, physiologic scores, diagnostics, plan (medications and procedures), assessment, and reevaluation. Software on a portable computer installed in an EMS response unit utilizes a graphical user interface for data collection by prehospital emergency care providers. A data set stores codes corresponding to user's selections. This data set supports data storage and analysis. The electronic PCR and data set can be useful to EMS agencies for collecting, storing, reporting, and analyzing information. RESULTS: Variables are categorized into 12 main categories to categorize the variables and to drive data collection. The system provides the user with the ability to print out a record (using a portable printer installed in an ambulance) and analyze data stored in the data set. CONCLUSION: This computerized approach overcomes many limitations inherent with using paper-based systems for research. Linked with emergency department, hospital discharge, and mortality data, EMS data can be used in systems analyses related to patient outcome.

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.

Prehospital advanced life support for major trauma: critical need for clinical trials.

A widely diverse body of information exists on the use of Advanced Life Support procedures by prehospital personnel. We compared and contrasted the literature that currently exists on this topic. We examined methodologies, results, and conclusions for each article. We also stress the need for critical clinical evaluations in this arena.

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.

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. EMS Agenda for the Future Steering Committee.

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.