Development of a Metropolitan Matrix of Primary Stroke Centers
The Phoenix Experience
Background and Purpose— In 1998, 2947 patients in metropolitan Phoenix were hospitalized for acute cerebral infarction. Only 2 of the 26 regional hospitals satisfied criteria for primary stroke center (PSC) designation. Fewer than 1% of patients with ischemic stroke received tissue plasminogen activator for thrombolysis. We sought to develop and evaluate the effectiveness of a metropolitan prehospital emergency medical system for effectively identifying and transporting patients with acute stroke to a matrix of predesignated PSCs and increasing to 20% the proportion of all such patients receiving tissue plasminogen activator.
Methods— The American Stroke Association Phoenix Operation Stroke partnered with the Arizona Emergency Medical Systems in 1998 to 1999 to list goals and objectives, identify key stakeholders, and develop committees to address community education, emergency medical system training, and PSC designation.
Results— Over 8 years, emergency medical system personnel were trained to identify and transport patients with acute stroke to PSCs, 8 hospitals met PSC criteria, the metropolitan matrix of PSCs became operational (in 2003), and 18% of patients with acute ischemic stroke received thrombolysis.
Conclusions— It is feasible to develop and operationalize a successful metropolitan-wide matrix of PSCs to accommodate emergency medical system-identified and transported patients with acute stroke in a 9000-square-mile region with a population of 3.5 million people.
- acute stroke
- community health services
- emergency medical systems
- primary stroke center
- thrombolytic therapy
- tissue plasminogen activator
Stroke is the third most common cause of death in the United States. Annual estimates of new cases of stroke approximate 700 000. One third of these patients die. Stroke is also the leading cause of adult disability.1 It results in substantial economic burden for patients, communities, and insurance providers.2
In 1997, a national consensus conference identified the need to establish primary stroke centers (PSCs) where patients could receive emergency stroke care from qualified teams of healthcare providers. The Brain Attack Coalition (BAC) furthered this recommendation with criteria for stroke center development.3 The Get With the Guidelines–Stroke program of the American Stroke Association (ASA) and the American Heart Association also promotes stroke center development.4 Finally, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) recently launched a disease-specific certification program for PSCs.5
Developing a citywide system in a metropolitan area for management of acute stroke victims is a complex endeavor. Obstacles impede progress at every link in the acute stroke chain of survival. Public recognition of stroke warning signs is poor, and facilitating change in prehospital care and transport procedures of emergency medical service (EMS) agencies is challenging.6 The reluctance of emergency department physicians to accept thrombolysis for stroke as a standard treatment looms large, and establishing the necessary protocols at each hospital is difficult.7,8 Despite these obstacles, the Houston Paramedic and Emergency Stroke Treatment and Outcomes Study successfully demonstrated that stroke center development can support the safe practice of thrombolytic treatment in community settings.9
We sought to develop a metropolitan matrix of PSCs closely linked with EMS agencies. Our purpose was to increase the number of eligible patients with ischemic stroke who received tissue plasminogen activator (tPA) for thrombolysis.
Subjects and Methods
Maricopa County is located in central Arizona. The 2003 US census reported a county population of 3 389 260, primarily in 47 cities spread out over 9224 square miles (23 891 km2). The county seat is Phoenix. The racial makeup is 52% white, 25% Hispanic or Latino, 4% black, 2% Native American, 2% Asian, and 15% other races.
The Bureau of Public Health Statistics within the Arizona Department of Health Services prepared a county summary of baseline data for resident hospitalizations for acute stroke in 1998.10 The report showed that 7091 persons were discharged from county hospitals with a principal diagnosis of acute cerebrovascular disease, which included International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes 430 through 437 (Table 1; Figure 1). A subset of these patients, 2947 (42%), was affected by occlusion with brain infarction (International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes 433 and 434).
In 1998, patients with acute ischemic stroke were distributed among 26 hospitals, as follows. One hospital admitted more than 300 annually, 3 admitted 200 to 300, 11 admitted 100 to 200, and 11 admitted fewer than 100. The age-adjusted hospitalization rate for occlusive stroke was 107.7 per 100 000 persons. The mean and median lengths of stay were 5 and 4 days, respectively. Analysis of hospital procedure codes from all 26 hospitals showed that only 4 of 2947 patients (0.1%) with acute ischemic stroke received thrombolysis. This alarmingly low rate emphasized the need for improvements.
Phoenix Operation Stroke
Operation Stroke (OS) was a nationwide initiative of the ASA that was implemented in 1998. Its major goal was to reorganize stroke services to provide better acute stroke care in the top 125 metropolitan communities across the United States. The strategic goal of the Phoenix OS initiative was to determine the best standard of acute stroke care (including public education, treatment, and survivor support) and to bring the community up to that standard.
An action goal was to increase the proportion of all patients with acute ischemic stroke who receive appropriate thrombolytic therapy on admission to a designated PSC within the 3-hour window to 20%.
Because new treatments were emerging to aid in diminishing stroke-related brain damage at the inception of OS, a tremendous learning curve existed among public and healthcare providers about stroke as a medical emergency, and less than 3% of patients with stroke nationally received early treatment.11,12 There were gaps in the delivery of acute therapy, rehabilitation, education, resources, and support services. The stroke chain of survival figured prominently in the development and implementation of the Phoenix Metropolitan Matrix of PSCs.
In 1998, the executive committee and 5 subcommittees of the Phoenix OS program were formulated. Leadership consisted of 2 elected executive committee cochairs (representing stroke neurology and emergency medicine) and 5 elected subcommittee chairs. Each subcommittee drafted goals and implementation plans. Committee membership represented key stakeholder areas, including neurology, emergency medicine, EMS, physical medicine and rehabilitation, neuroradiology, nursing, the ASA, and administrative officers from each hospital. All members, apart from salaried ASA staff, volunteered their time and expertise to meet and carry out the requisite work.
The community education subcommittee focused on an annual community education and stroke screening program called StrokeCheck traditionally held during May, the nationally designated stroke month. Since the inception of StrokeCheck in 2000, approximately 6000 people have undergone screening in Phoenix. At each StrokeCheck site, participants complete a stroke risk assessment and watch an ASA acute stroke education videotape. Participants undergo assessment of vital signs and carotid bruit auscultation. Local media outlets advertise the program and promote the key public education takehome messages.
Emergency Medical Services
The ASA produced an instructional video for EMS provider education that included information about the pathophysiology of stroke, the 3-hour timeframe for thrombolysis, the 7 links of the stroke chain of survival, the EMS protocol for recognition of acute stroke using the Cincinnati Prehospital Stroke Scale, recording of time of symptom onset (or the time the patient was last known to be symptom-free), the assessment of serum glucose, and support of airway, breathing, and circulation. Additional video content included monitoring neurological status, obtaining intravenous access, using isotonic crystalloid solution, obtaining an electrocardiogram, treating seizures if applicable, prenotifying the treatment center of the estimated time of arrival, and providing rapid transport to the closest PSC emergency department.
EMS providers were also shown a video enactment of an acute stroke victim and optimal prehospital treatment. Between December 1999 and January 2000, the EMS subcommittee designed a standardized stroke training module and slide set based on a stroke education needs assessment completed by 897 EMS personnel and 173 operators.
Phoenix Metropolitan Emergency Medical System
The Phoenix metropolitan region is served by an advanced life support, fire department-based EMS system. Twenty-four cities work together with borders selected by global positioning in real time. Primary EMS care is provided by crosstrained, dual-role firefighter–paramedics. The fire engines respond first to all 911 requests. Ambulance transport is provided by fire department or subcontracted ambulances.
Arizona Emergency Medical Systems
Arizona Emergency Medical Systems, Inc (AEMS), a 501(c)(3) nonprofit organization, is a community-based volunteer organization dedicated to improving EMS agencies for central Arizona. Since 1974, AEMS has brought together physicians, nurses, EMS personnel, and hospital administrators to ensure coordinated delivery of emergency medical care that meets the needs of the public.
Primary Stroke Center Designation
After launching initiatives to improve acute stroke care in Phoenix in 1998 to 1999, OS and AEMS initiated the PSC evaluation and designation process in 2000. The mandate was for hospitals designated as PSCs to form a citywide matrix that preferentially accommodates patients with acute stroke. The AEMS plan was for EMS providers to triage patients with acute stroke for transport directly to the nearest PSC. Modified PSC criteria were based on the published criteria of the BAC.3
To obtain the PSC designation, hospitals provided an emergency department protocol for administration of tPA (in compliance with American Academy of Neurology or ASA guidelines)13; a list of physicians (preferably neurologists) experienced in administering tPA for stroke who had to be present when it was administered; a list of neurologists participating in the 24/7 on-call roster who were capable of assessing the patient within 45 minutes of being paged; a list of neurosurgeons participating in the 24/7 on-call roster who were capable of assessing a patient within 2 hours of being paged (or a hospital transfer protocol for facilities without neurosurgical support); stroke clinical pathways or preprinted order sets addressing acute stroke treatment, prevention, and rehabilitation; a list of members of a stroke steering committee and minutes from a recent meeting; the name and duties of the medical director of the stroke unit; documentation of stroke education and training programs for staff; a list of stroke care quality indicators or performance measures monitored by the hospital; the daily availability of MRI, magnetic resonance angiography, CT, transthoracic echocardiography, transesophageal echocardiography, carotid ultrasound, and cerebral angiography; and data from the last 6 consecutive patients who received tPA for acute ischemic stroke revealing symptom-to-needle times, door-to-needle times, door-to-CT times, door-to-laboratory times, and disposition after arrival in the emergency department.
After these criteria were established, all existing Phoenix hospitals were surveyed by questionnaire for PSC designation readiness. Prepared hospitals were invited by OS and AEMS to apply for the PSC designation, and unprepared hospitals were encouraged to develop the resources necessary to become a PSC.
An OS and AEMS site visit team included a neurologist, an emergency physician, and an ASA representative who met with the hospital’s stroke steering committee and stroke unit medical director. After confirming compliance with each of the modified BAC criteria, the team questioned personnel in key areas of the hospital (eg, emergency department, radiology, pharmacy, laboratory, intensive care unit, stroke unit, and rehabilitation unit). After the site visit, team members prepared a formal summary of their observations for the executive committee, and a final decision about PSC designation was reached by consensus.
Coincident with OS and AEMS communicating this decision to successful hospitals, the newly designated PSC was added to the matrix. Hospitals with unsuccessful applications were encouraged to reapply and undergo a repeat site visit after demonstrating full compliance with recommendations for correction of documented deficiencies.
This study was approved by the Human Subject Research Board of the Arizona Department of Health Services.
Hospital Survey Results
Results from the Phoenix hospital survey revealed many deficiencies in 1998 (Table 2). Only 2 of the 26 hospitals met every BAC criterion. The other 24 had at least one deficiency each.
Description of Primary Stroke Center Designation
The map of Maricopa County and metropolitan Phoenix (Figure 2) shows existing fire stations, existing hospitals, and the 8 PSCs. Six hospitals were designated as PSCs on September 29, 2003: Mayo Clinic Hospital (surveyed April 21, 2003), St Joseph’s Hospital and Medical Center (surveyed April 23, 2003), Banner Good Samaritan Medical Center (surveyed June 5, 2003), Banner Thunderbird Medical Center (surveyed June 10, 2003), and Sun Health Boswell Hospital and Sun Health Del E. Webb Hospital (both surveyed April 16, 2003). Arrowhead Hospital was surveyed April 28, 2004, and designated May 1, 2004, and Scottsdale Healthcare Osborn was surveyed April 24, 2005, and designated June 1, 2005.
The phrase “metropolitan matrix of PSCs” was carefully selected to describe a large geographic community or city environment in which a collection of specially designated stroke hospitals is developed, which then interacts with a sophisticated preexisting EMS system. The word “matrix” is defined in the Compact Oxford English Dictionary as “an environment or material in which something develops.”14 The present 8 PSCs were chosen not by geographic location, but by their willingness and capabilities to meet BAC criteria. After the matrix became fully operational, we recognized that some regions of the valley (eg, the southeast) were relatively underserviced by PSCs in comparison with others (eg, the central). Efforts are underway to assist and encourage existing hospitals to assemble the necessary personnel and resources to operate as PSCs.
Estimated Cost Analysis
We estimated a total cost of $3 547 300 for development and maintenance of OS in Phoenix during 1998 to 2005. The ASA staff salary was $30 000 per year ($240 000 for 8 years). One-time costs were for the survey ($5000) and the printed EMS teaching module ($7500). The training of EMS staff members costs $19 600 annually, and the estimated value of 6276 hours of volunteer physician and health professional time was $3 138 000 (at $500 per hour).
Phoenix Metropolitan Matrix of Primary Stroke Centers: Thrombolysis Treatment (2004 to 2005)
Over a 12-month period (July 2004 to June 2005), the 8 participating PSCs admitted a total of 1800 patients with acute ischemic stroke (Table 3). Of these 1800, 61% (1104) presented to the emergency department within 3 hours of stroke symptom onset (or time last known to be symptom-free). Of these 1104 early arrivers, 47% (520) were eligible for intravenous tPA. Of these 520 patients, 62% (320) actually received intravenous tPA. The main reasons for not administering tPA to eligible patients were (1) perceived mild or rapidly resolving deficits; (2) insufficient time for patients who presented 2 to 3 hours after symptom onset; (3) advanced age; (4) preexisting neurological or functional deficits; (5) dementia; or (6) the discretion of the treating emergency physician or neurologist.
Thrombolysis Administration at 8 Phoenix Primary Stroke Center Hospitals Before and After Designation
As indicated earlier, 4 patients (0.1%) with acute ischemic stroke received tPA in 1998 in all of Maricopa County. The proportion of ischemic stroke patients receiving tPA among the 8 study hospitals that year was 0.28% (4 of 1454; Figure 3). After the PSC designation, in July 2004 through June 2005, a total of 320 patients received tPA, and the proportions treated at each hospital increased substantially (range, 3.8% to 30.0%). Half of the 8 matrix PSCs met or exceeded the 20% treatment target. The overall mean proportion treated was 18% (Figure 3).
The successes of the program included acknowledgement of the need for improved metropolitan acute stroke care, involvement of multiple stakeholders, development of a list of strategic goals, use of needs assessments, maintenance of communication among stakeholders, development of a plan to address deficiencies in the system, competition among hospitals, designation of PSCs, and construction of a metropolitan matrix of PSCs. The obstacles were difficulty maintaining momentum; keeping pace with staff turnover and new roles; addressing administrative issues in organizations (ASA, OS, and AEMS); the enormous geographic area and population (one PSC serving an average of 1125 square miles and an average population of 437 500); and the large number of hospitals within the Phoenix area.
Future plans include evaluation of the effectiveness of the matrix with the Arizona Stroke Prehospital Identification Registry and Education program, a Maricopa County registry of patients with acute stroke.15,16 Plans also include post-EMS training evaluation and integration of stroke certification by JCAHO with the OS PSC designation process. Other plans include conducting a review of the preparedness of additional metropolitan hospitals and encouraging nonparticipating hospitals to become PSCs.
Phoenix OS, now known as the Phoenix Stroke Initiative, has proposed using JCAHO PSC certification criteria for certifying and recertifying Phoenix PSCs. Two of the 8 Phoenix Metropolitan Matrix PSCs were awarded JCAHO PSC certification in 2006, joining the present 366 healthcare organizations nationwide that are PSC-certified.5 The Phoenix Stroke Initiative will be ideally suited to facilitate the certification process for comprehensive stroke centers after JCAHO has developed the criteria and assessment process. We estimate that at least 2 of the present PSCs would immediately qualify as comprehensive stroke centers by the BAC criteria.
To double-check the tPA administration data submitted by PSCs in the matrix, we consulted Genentech, Inc (South San Francisco, Calif) to determine the numbers of vials of tPA sold in Phoenix for stroke during a 12-month period (July 2004 to June 2005). The equivalent of 307 (100-mg) vials was sold to PSC hospitals in Phoenix. This number approximates the collective PSC report of 320 patients treated with tPA.
The Phoenix Metropolitan Matrix of PSCs probably serves only 60% of the city’s patients with acute stroke.15,16 We cannot yet track the use of thrombolysis at Phoenix hospitals outside the matrix. However, tPA sales data indicate that no more than 17 (100-mg) vials of tPA were sold to non-PSC hospitals in Phoenix for treatment of stroke. Thus, we estimate that only 1.4% (17 of 1200) of patients with ischemic stroke presenting to a non-PSC received thrombolysis compared with 18% at matrix PSCs.
It is difficult to estimate the effectiveness of StrokeCheck in improving public knowledge about the warning signs of stroke, the need to call 911, and the 3-hour time window for thrombolysis. Although immediate and retained knowledge from this community program have not been formally assessed, we estimate that public education initiatives form only one part of this multitiered initiative. Community stroke-screening initiatives similar to StrokeCheck have had a modest effect on knowledge of stroke warning signs. DeLemos et al17 showed that knowledge of stroke warning signs increased from 59% to 94% after screening but decreased to 77% at 3 months.
Within the matrix, 61% of patients with acute ischemic stroke arrived at a PSC within 3 hours of symptom onset (or time last known to be well). This proportion is high compared with published reports of 19% to 60% of patients with stroke presenting to the emergency department within 3 hours.18–21 We suspect that this high proportion of early presenters resulted from socioeconomic factors in the study population and from the education and training provided by repeated annual public education initiatives such as StrokeCheck during the study period.
The TLL Temple Foundation Stroke Project showed that educational interventions on stroke identification and management targeting patients, EMS, hospitals, and community physicians increased the use of thrombolytics for ischemic stroke from 2.2% to 8.7% (versus Phoenix PSCs, 18%), whereas communities without such programs saw only a 0.06% increase.22 Rates of tPA use increased from 14% to 52% (versus Phoenix PSCs, 62%).22 Benefits from these aggressive multitiered interventions were sustained.23,24
In Houston, Texas—a large, highly populated, multiethnic city with a similar number of annual patients with acute stroke—the Houston Paramedic and Emergency Stroke Treatment and Outcomes Study involved 6 of a possible 9 hospitals comprising most acute stroke admissions.9 Hospital, paramedic, and patient data were collected prospectively during preintervention and active intervention phases on suspected patients with acute stroke admitted by Houston Fire Department–EMS Services. A similar multitiered educational intervention included paramedic, hospital, and community education. Thrombolysis rates increased in 4 of 6 centers (versus Phoenix PSCs, 8 of 8) and modestly overall from 10.6% before to 12% after (versus Phoenix PSCs, 1.1% to 18.0%). The Houston Paramedic and Emergency Stroke Treatment and Outcomes Study began about the same time as our project (1999) but had a shorter evaluation period (September 1999 to March 2001). In contrast, our evaluation period extended 8 years, into 2005, thereby allowing greater time for education and initiatives to mature.
The certification of hospitals as PSCs is progressing rapidly. An ASA expert panel concluded that several useful certification processes could be developed from the BAC framework for improved care and outcomes.25 Data suggest that unbiased independent evaluations of hospitals as PSCs should lead to more accurate assessment of a facility’s true capabilities. Self-certification should be discouraged because it leads to overestimation of a hospital’s compliance with recommendations for a PSC.26 The Phoenix Metropolitan Matrix of PSCs is in compliance with the present ASA recommendations: (1) creation of PSCs is strongly recommended (class I, level B), but the organization of such resources will depend on local variables and resources; (2) the development of comprehensive stroke centers is recommended (class I, level C); (3) certification of PSCs by an external body such as JCAHO is encouraged (class I, level B). The panel strongly encourages additional medical centers to seek such certification; and (4) for patients with suspected stroke, EMS personnel should bypass hospitals without the resources to treat stroke and seek the closest facility capable of treating acute stroke (class I, level B).27
The design and analysis of results in a project of this type have several limitations. The baseline data were derived from the 1998 report of stroke hospitalizations in Maricopa County. Only discharges from nonfederal facilities were included. The addition of stroke cases at Department of Veterans Affairs and Indian Health Service facilities would have increased the total. The analyses assume that the diagnosis and procedure coders conducted their assignments of principal diagnosis and procedure codes uniformly. The chart auditing by Medicare and managed care payers helped ensure that this assumption was reasonable. Stroke cases were missed if the stroke code was posted in a field other than the principal diagnosis field.
The limitations of the follow-up data from July 2004 through June 2005 include each institution submitting stroke data to the ASA without a standard format. Subsequently, 6 of 8 hospitals elected to participate in ASA’s Get With the Guidelines–Stroke program and to use this as the principal stroke outcomes collection and analysis tool. Also, we discovered that fewer than 50% of the true stroke thrombolysis cases at some hospitals were correctly coded with International Classification of Diseases, Ninth Revision, Clinical Modification procedure code 99.10.28
Summary and Conclusion
In 1998, 2947 patients in Maricopa County were discharged from 26 hospitals with a diagnosis of acute cerebral infarction. Only 2 of these regional hospitals satisfied all the criteria required for PSC designation, and only 0.1% of patients with acute ischemic stroke received tPA. Phoenix OS partnered with AEMS during 1998 to 1999 to list goals and objectives, identify key stakeholders, develop committees to address community education, conduct EMS training, and obtain PSC designation. Over 8 years, from 1998 to 2005, EMS personnel were trained to identify and transport patients with acute stroke to PSCs, and 8 metropolitan hospitals subsequently met criteria for PSC designation; the Phoenix Metropolitan Matrix of PSCs became operational in September 2003 with the first 6 PSCs. A plan to evaluate effectiveness is underway.
Developing a successful metropolitan matrix of PSCs to accommodate patients with acute stroke identified and transported by EMS agencies in a region of 47 cities covering 9000 square miles with a population of 3.5 million is feasible. Eighteen percent of all patients with ischemic stroke who presented to a participating hospital in the Phoenix Metropolitan Matrix of PSCs received tPA.
Phoenix Operation Stroke Executive Committee (at inception): Timothy J. Ingall, MD, PhD, Mayo Clinic; John Raife, MD, St Joseph’s Hospital; Scott Agran, MD, Sun Health Systems; James L. Frey, MD, Barrow Neurological Institute; John Kozak, MD, Mesa Lutheran Hospital; Bruce Barnhart, RN, CEP, LifeNet Air Med of Arizona; David W. Heath, CHES EMT-B, American Heart Association; and Mary Lee Hyatt, American Heart Association.
On behalf of the Phoenix Metropolitan Matrix of Primary Stroke Centers: Mayo Clinic Hospital, St Joseph’s Hospital and Medical Center, Banner Good Samaritan Medical Center, Banner Thunderbird Medical Center, Sun Health Boswell Hospital, Sun Health Del E. Webb Hospital, Arrowhead Hospital, and Scottsdale Healthcare Osborne.
We acknowledge the Phoenix Operation Stroke Executive Committee, the Arizona Emergency Medical Systems, Inc, the American Stroke Association, the Arizona Department of Health Services, and the Phoenix Metropolitan Matrix of Primary Stroke Centers for assistance with compiling data and supportive documents, editing the manuscript, and providing constructive feedback. We thank Nichole L. Boruff for graphic design of figures. Editing, proofreading, and reference verification were provided by the Section of Scientific Publications, Mayo Clinic.
Source of Funding
Funding for this study was provided by the American Stroke Association.
Portions of this manuscript have been published in abstract form by the American Neurological Association, 2005. Presented at the 2005 American Stroke Association International Stroke Conference, New Orleans, Louisiana, February 2 to 4, 2005.
- Received August 24, 2007.
- Accepted September 10, 2007.
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