Diagnostic Imaging of Ischemic Stroke in the Emergency Room Setting: Implementation Considerations - CADTH ENVIRONMENTAL SCAN REPORT






8    Diagnostic Imaging of
9    Ischemic Stroke in the
10   Emergency Room Setting:
11   Implementation
12   Considerations
31   Authors: Michael Raj, Charlotte Wells, Melissa Severn
32   Cite As: Diagnostic Imaging of Ischemic Stroke in the Emergency Room Setting: Implementation Considerations.
33   Ottawa: CADTH; 2018 May. (Environmental Scan; Issue XX).
35   Disclaimer: The Environmental Scanning Service is an information service for those involved in planning and
36   providing health care in Canada. Environmental Scanning Service responses are based on a limited literature
37   search and are not comprehensive, systematic reviews. The intent is to provide information on a topic that
38   CADTH could identify using all reasonable efforts within the time allowed. Environmental Scanning Service
39   responses should be considered along with other types of information and health care considerations. The
40   information included in this response is not intended to replace professional medical advice nor should it be
41   construed as a recommendation for or against the use of a particular health technology. Readers are also
42   cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness, particularly in
43   the case of new and emerging health technologies for which little information can be found but that may in future
44   prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are
45   accurate, complete, and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for
46   any loss or damages resulting from use of the information in the report. Copyright: This report contains CADTH
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49   Internet.
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     CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
     Setting: Implementation Considerations

56   Context
58   Stroke is the third leading cause of death and the main cause of adult disability in Canada.1
59   The average patient irretrievably loses 1.9 million brain cells each minute in which stroke is
60   untreated.1 To halt the progression of irreversible brain tissue damage, swift treatment is
61   required. The goal of neuroimaging is to improve the outcome of stroke by quickly making
62   the correct diagnosis and enabling immediate treatment. Since patients cannot be treated
63   until they are imaged, the rapid acquisition and interpretation of imaging studies is critical for
64   improved outcomes.2
66   There are four main types of stroke: ischemic, hemorrhagic, covert, and transient ischemic
67   attack.3 The most common is ischemic,3 accounting for approximately 80% of acute strokes.4
68   The purpose of the first imaging procedure performed in patients with suspected stroke is to
69   distinguish between hemorrhagic and ischemic stroke, which is needed for the appropriate
70   management of acute stroke. 4 Imaging can also contribute to efficiencies in stroke systems
71   of care by assisting physicians in making decisions regarding the transfer of patients with
72   acute ischemic stroke from primary stroke centers to centers capable of performing
73   endovascular procedures.5
75   Non-contrast computed tomography (CT) is the most widely used first line imaging modality
76   for the diagnosis of suspected acute stroke.6 The test rules out hemorrhage and other
77   conditions that mimic stroke.7 However, there are many other imaging modalities that can be
78   used to investigate acute stroke.
80   Other factors that determine optimal use of imaging modalities include availability of skilled
81   technicians and specialist physicians, access, physician preferences, and costs.8
82   Geographical dispersion is also a barrier to the successful outcome of timely diagnosis of
83   ischemic stroke.9,10 There is uncertainty as to which implementation strategies for optimal
84   imaging have been used in the Canadian emergency care setting, and which have been the
85   most successful.
87   Objectives
89   The objective of this Environmental Scan is to identify and summarize information regarding
90   the implementation considerations for diagnostic imaging of acute ischemic stroke in the
91   Canadian emergency care setting. The following questions are addressed:
93      1. What are the current diagnostic imaging modalities used for ischemic stroke
94         diagnosis in the emergency setting in Canadian jurisdictions?
96      2. What types of ischemic stroke imaging modalities are accessible in Canadian
97         jurisdictions across urban, rural, and remote health care settings?

     CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
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99      3. What are the main challenges and enablers of diagnosing ischemic stroke in the
100         emergency setting in Canadian jurisdictions?
102   Methods
103   Approach
104   To understand implementation issues associated with diagnosing ischemic stroke in
105   Canadian emergency care settings, a dual-stage, sequential research protocol was followed.
106   The two stages included 1) consultation with targeted key stakeholders (informants), and 2)
107   a review of the published and grey literature. Findings from the literature search were used
108   to supplement the information retrieved during the consultations.
110   Data Collection
111   Stage 1: Consultations
112   Consultations were conducted with targeted key informants identified through the clinician
113   networks managed by the CADTH Implementation Support and Knowledge Mobilization
114   team or referred through other informants during consultations. These key informants were
115   consulted in order to provide a general overview of policy, practice and implementation
116   issues related to imaging modalities in diagnosing ischemic stroke in Canadian emergency
117   care settings as well as to identify relevant literature. To guide the consultations, a semi-
118   structured interview guide was developed (Appendix 2). Interview questions were developed
119   based on research questions and were related to the general approach to diagnosing
120   ischemic stroke in the emergency room, challenges and supports to the diagnosis of
121   ischemic stroke, the implementation of strategies, as well as gaps in the literature.
122   Consultations took place between August and November of 2017 and consent to publish
123   comments and names were obtained from key informants.
125   Stakeholder feedback will be solicited by posting a draft version of the report on CADTH’s
126   website and by emails to subscribers to CADTH’s mailing lists. Key informants involved in
127   the consultations will also be asked to provide feedback.
129   Stage 2: Literature Search
131   Search Methods

132   The literature search was performed by an information specialist, using a peer-reviewed
133   search strategy.

134   Implementation-related information was identified by searching the following bibliographic
135   databases: MEDLINE (1946–) with in-process records and daily updates, Embase (1974–)
136   via Ovid; CINAHL (1981–) via EBSCO; and PubMed. The search strategy is comprised both
137   controlled vocabulary, such as the National Library of Medicine’s MeSH (Medical Subject
138   Headings), and keywords. The main search concepts were stroke, diagnostic imaging,
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

139   Canada, and key terms for implementation issues. No methodological filters were applied to
140   limit retrieval by study design. Retrieval was limited to documents published since January 1,
141   2007. Results were limited to English- and French-language publications.
143   Grey literature (literature that is not commercially published) was identified by searching the
144   Grey Matters checklist (https://www.cadth.ca/grey-matters), which includes the websites of
145   HTA agencies, clinical guideline repositories, SR repositories, economics-related resources,
146   public perspective groups, and professional associations. Google and other Internet search
147   engines will be used to search for additional Web-based materials.
149   Selection Criteria

150   English- or French-language reports that described implementation and context issues,
151   including barriers (or challenges) and facilitators (or enablers) associated with diagnosis and
152   imaging of ischemic stroke in the emergency department were eligible for inclusion.

153   Screening and Selecting Articles for Inclusion and Data Extraction

154   Citations arising from the literature searches were screened independently by one reviewer
155   for information related to implementation issues in Canada. From each potentially relevant
156   article, one reviewer extracted the bibliographic details (i.e., the authors, the year of
157   publication, and the country of origin), and data, which was organized under the
158   INTEGRATE-HTA framework.11 The information from the identified literature supplemented
159   the information provided by the consultations, and attempted to address potential information
160   gaps.

161   Descriptive analysis and synthesis
162   Responses from consultations were used to address Questions 1 and 3. Data from CADTH’s
163   Canadian Medical Imaging Inventory report (2017)12 was used to address Question 2. All
164   research questions were supplemented with information obtained through the literature
165   search. Additionally, stakeholder feedback will be used to supplement information received
166   from the consultations and literature search.
168   Information from consultations and findings from the literature were sorted into categories
169   based on the domains identified by the Context and Implementation of Complex
170   Interventions (CICI) framework from INTEGRATE-HTA11 to identify themes related to the
171   strategies used to improve timely access to the diagnosis of ischemic stroke in the Canadian
172   emergency setting.

173   The framework helps to examine the influence of context and implementation issues as
174   modifiers in an HTA, and factors enabling or limiting intervention uptake.
176   The concept of context within the framework is considered to be a set of characteristics or
177   circumstances that interact, influence, modify, facilitate, or constrain the intervention and its
178   implementation. Implementation, for the purposes of the framework, is considered to be an
179   actively planned and deliberately initiated effort with the intention of to bring a given object
180   into policy and/or practice.11
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

182   Using this framework, the domains of context, socio-economic, socio-cultural, setting,
183   political, legal, geographical, ethical, and epidemiological, were used to guide the
184   categorization of information on challenges and enablers of diagnosing ischemic stroke in
185   the emergency setting in Canadian jurisdictions. The four domains of implementation,
186   provider, organization and structure, policy, and funding, as well as the additional domain of
187   patient were used to further guide the categorization of identified strategies, barriers, or
188   supports as they relate to the implementation of diagnostic strategies across the various
189   levels of health care service delivery.

191   Findings
192   Consultations
193   In total, nine key stakeholders were interviewed for the purposes of this environmental scan
194   (Appendix 1). This included three physicians (two emergency room physicians and one
195   stroke neurologist); four health system administrators including provincial Ministry of Health
196   representatives tasked with management or coordination of stroke services for their
197   jurisdiction; one paramedic with considerable involvement with stroke services in his
198   province; and one researcher representing a national special interest group in the stroke
199   community.
200   Through these consultations, there was representation for the following provinces: British
201   Columbia (BC), Alberta, Saskatchewan, Ontario, Nova Scotia and Prince Edward Island
202   (PEI). While all stakeholders represented were based in urban environments, all were
203   knowledgeable in the issues related to rural and remote settings as related to stroke care or
204   served populations in these settings as well.
205   Efforts were made to contact stakeholders in other Canadian jurisdictions. No response was
206   received from Manitoba, Nunavut, the Northwest Territories (NWT), Yukon, Quebec, New
207   Brunswick, or Newfoundland and Labradorby by the deadline for consultation.
209   Literature Search
210   The literature search yielded 410 citations, of which 18 studies were determined to be
211   eligible to address the research question. Twelve articles were published in Canada,8-10,13-21
212   three articles were published in the United States (US),22-24 one article was from
213   Switzerland,25 and one article was from both the US and Canada (an international
214   collaboration).26 Additionally, a Rapid Response report was authored by CADTH which was
215   not specific to the Canadian context.27 Three articles focused on imaging or best practice
216   recommendations,10,20,24 three articles focused on telestroke,13,18,20 three articles focused on
217   access to stroke care,8,9,26 and one article focused on stroke education in emergency
218   medical residency programs.21 The remaining articles pertained to quality of stroke care,
219   experiences with portable CT scanners, stroke protocols, field recognition and accuracy of
220   stroke diagnoses, and other related neuroimaging articles.14-17,22,23,25,27
221   Findings below are presented by research question.
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223   What are the current diagnostic imaging modalities used for ischemic stroke
224   diagnosis in the emergency setting in Canadian jurisdictions?
226   Non-contrast computed tomography (NCCT) is considered by many to be useful in its ability
227   to address imaging requirements for stroke assessment.6 Other imaging modalities are also
228   used, including CT angiography (CTA), multiphase CTA, CT perfusion (CTP), multimodal
229   MRI, MR perfusion (MRP), MR angiography (MRA), and ultrasound. Magnetic resonance
230   imaging (MRI) is also used, although less frequently and contingent on availability, suitability
231   and time.25
233   CT is the imaging modality available in most hospitals on a round-the-clock basis. While CT
234   is more widely available, MRI can provide additional information compared with CT, and is
235   more sensitive to small infarctions. 25 However, MRI may not be suitable for all patients as
236   some patients are contraindicated for MRI scanning (e.g., are claustrophobic, have
237   pacemakers, or have metal in the body), thus CT scanning is recommended.27
239   The choice of CT or MRI imaging is based on the available infrastructure and staff, as well
240   as the experience of the stroke team. The choice of modality depends on the infrastructure,
241   the logistics, the expertise of the stroke team.25 It also may depend on physician preferences
242   and logistical factors such as whether advanced imaging, especially MRI, can be performed
243   quickly and on a 24/7 basis.24 The choice of modality is also dependent on other factors
244   which are described below.
246   Access to imaging modalities can be an enabler to timely stroke diagnosis. The
247   consultations conducted with informants working in either urban, rural, or remote settings or
248   with knowledge of the imaging capabilities across jurisdictions, indicated that CT is the
249   primary diagnostic imaging strategy used to diagnose ischemic stroke across all Canadian
250   jurisdictions consulted with. While most of these modalities are available in urban, acute care
251   centers, rural facilities tend to have on-site access to CT and ultrasound while some may
252   also have CTA capabilities. Conversely, access to imaging modalities can be a barrier to
253   timely stroke diagnosis. The consultations also highlighted that remote health care facilities
254   generally do not have these services available and will send patients to the nearest, most
255   appropriate site that can offer access to these modalities. Further information regarding the
256   accessibility and availability of imaging modalities across Canada and in various Canadian
257   jurisdictions is outlined below.
259   What types of ischemic stroke imaging modalities are accessible in Canadian
260   jurisdictions across urban, rural, and remote health care settings?
262   CT imaging is the most common and widely used imaging modality for stroke in Canada.6
263   MRI is also used in the diagnosis of stroke, however less frequently than CT scanning.6
264   Single-photon emission computed tomography (SPECT) and positron emission tomography
265   (PET) scanners are also used in neurology to visualize brain physiology.28 PET is
266   considered gold standard for measuring brain physiology, but is not generally used in the
267   acute stroke setting as it is not considered practical, due to the long interval between probe
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
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268   injection and imaging, the relatively smaller number of PET scanners available 24/7, and
269   difficulties for the stroke patient to remain still during imaging.29,30
271   To determine what stroke imaging modalities are accessible in Canadian jurisdictions in a
272   variety of health care settings, data from the 2017 Canadian Medical Imaging Inventory
273   (CMII) was used.12 The CADTH CMII report provides an update on the availability and use of
274   specialist imaging equipment across the country. Data is provided from a web-based survey
275   of private or public health care settings that operate medical imaging equipment,
276   supplemented by provincial data validators. The most recent survey was completed in 2017.
278   Data from the CMII survey indicated that there are 561 computed tomography (CT)
279   scanners, 366 magnetic resonance imaging (MRI) scanners, 51 positron emission
280   tomography (PET) CT scanners, 3 PET-MRI scanners, 330 single-photon emission
281   computed tomography (SPECT) scanners, and 261 SPECT-CT scanners in Canada, as of
282   2017.12
284   The majority of CT scanners are located in Ontario (32.7%) and Quebec (29.1%), with the
285   least number of CT scanners available in Nunavut, NWT, and Yukon. Each province has
286   access to at least one CT scanner. Per one million people, Ontario has 13.0 CT scanners,
287   whilst Nunavut, NWT and Yukon have 26.5, 22.7, and 26.4 respectively. The highest number
288   of CT scanners per million residents is in Newfoundland and Labrador, at 30.3.12
290   The majority of MRI scanners are also located in Ontario (33.1%), and there are 8.5 MRI
291   scanners per million people in Ontario. However, there are no MRI scanners in NWT or
292   Nunavut. Per one million residents, Yukon has the highest number of MRIs, at 26.5.12
294   There are only three PET-MRI scanners available in Canada, and all three are located in
295   Ontario. PET-CT scanners are available in nine provinces, with the majority located in
296   Quebec (41.2%). Per one million residents, New Brunswick has the most PET-CT scanners
297   available (2.6).12
299   SPECT is also available in nine provinces, with the majority available in Ontario (45.8%).
300   Ontario also has the most SPECT scanners available per one million residents, at 10.7.
301   SPECT-CT scanners are also most abundant in Ontario and Quebec (29.9% and 29.1%
302   respectively). Newfoundland and Labrador have the most SPECT-CT scanners available per
303   one million residents, at 17.12
305   Rural, Remote, and Urban Healthcare Settings
307   The 2017 CMII survey also collected information on the setting in which the healthcare
308   facility is located – this was self-reported as “urban”, “rural” or “remote”. 31 The 39.9% of sites
309   who responded to this part of the survey their setting amounted to 46.5% of imaging units
310   available in Canada.31

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312   Urban settings contained the majority of stroke imaging modalities, ranging from 75.4% of
313   CT scanners to 85.5% of MRI scanners. Rural settings contained 23.1% of CT scanners,
314   14.5% of MRI scanners, 11.4% of SPECT scanners, and 10.3% of SPECT-CT scanners.31
315   There are four CT scanners available in remote regions in Canada.31 Table 3 and 4 provide
316   additional details regarding urban, rural, and remote settings and the imaging modalities
317   available.31
319   What are the main challenges and enablers of diagnosing ischemic stroke in
320   the emergency setting in Canadian jurisdictions?
322   Geography and Setting
324   The INTEGRATE-HTA domain of geography refers to the broader physical environment,
325   landscapes and resources, available at a given location. Issues of geography can refer to
326   infrastructure (e.g., transportation), access to health care, and geographical isolation, etc.11
327   The setting domain according to INTEGRATE-HTA encompasses the immediate physical
328   and organizational environment, in which an intervention is delivered. It also comprises the
329   effect the location has on affected stakeholder. Issues of setting can refer to region, country
330   (e.g., urban and rural), or type of facility.11
332   Several articles reviewed pointed to the challenge posed by Canada’s vast geography,
333   varying size of regions and provinces, and larger proportion of rural and remote communities
334   in accessing care.10,13,14,32 These issues coupled with Canada’s challenging landscapes and
335   climate can limit the speed of access to hospital in time for treatment, even with fast door-to-
336   treatment times.9,14 One of the biggest factors in delays of prompt neuroimaging is the arrival
337   to the hospital from a setting other than home, and the presentation to rural hospitals versus
338   urban hospitals (even if neuroimaging is available at rural locations).17 The distance between
339   the patient and the hospital contributes to non-timely diagnosis.9 In rural areas, the distance
340   makes accessing emergency medical services (EMS) difficult for urgent conditions, including
341   stroke.9
343   In widely dispersed regions with long distances between a more comprehensive stroke
344   center and regional (rural) stroke center, diversion of patients to comprehensive centers has
345   the potential to substantially improve outcomes.15 Dr. Eddy Lang indicated that in more
346   remote locations of Alberta, patients who meet certain key symptoms of stroke such as
347   speech disorder, extremity weakness, or lack of consciousness, will usually have to be flown
348   out of the community via air ambulance (Dr. Eddy Lang, Alberta Health Services, Calgary,
349   AB: personal communication, 2017 Aug 8). Lori Latta, a project manager supporting stroke
350   initiatives for the Saskatchewan Ministry of Health, indicated that in Saskatchewan the use of
351   air ambulances to transport patients from remote (northern) areas is fairly common given its
352   geography, although volume of stroke patients from those regions is typically low (Ms. Lori
353   Latta, Project Manager, Clinical Pathways Ministry of Health, Saskatchewan: personal
354   communication, 2017 Nov 17).
356   A Canadian study found access to specialized services varying greatly across Canada. In
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

357   general, rural communities in Canada tend to have limited access to advanced neuroimaging
358   or stroke specialists, and small hospitals may have minimal or no access to diagnostic
359   services.9,16The vastness of regions in larger provinces with a large proportion of rural areas
360   also contributes to untimely diagnosis.32 Additionally, even with access to imaging at rural
361   hospitals, individuals presenting with symptoms to rural hospitals were less likely to receive
362   timely neuroimaging when compared to urban hospitals.17 One possible explanation for this,
363   according to Dr. Patrice Lindsay is that regional centers in Canadian rural settings tend to
364   experience longer wait times because the emergency room is also the trauma center and
365   cardiac center and there is no local option of a specialized stroke center (Dr. Patrice
366   Lindsay, Director, Stroke, Heart & Stroke (National), Ottawa, Ontario: personal
367   communication, 2017 Sep 12).
369   Access to Diagnostic Services and Imaging
370   According to Dr. Devin Harris there is a gap in access to CT in rural and remote areas in BC
371   (Dr. Devin R. Harris, Medical Advisor, Stroke Services BC: personal communication, 2017
372   Aug 22). Furthermore, current clinical practice guidelines state that CT tests must be
373   performed when ischemic stroke is suspected, though this technology is not always available
374   in rural or remote emergency departments.27 Because of this, Dr. Harris added, patients in
375   BC being transported by EMS often need to bypass their local center to get to one that has
376   the technology (Dr. Devin R. Harris: personal communication, 2017 Aug 22). Dr. Eddy Lang
377   furthered this by noting that, while some rural facilities in Alberta may have a CT scanner,
378   stroke patients may still require a transfer to a regional center where CTA is available (Dr.
379   Eddy Lang: personal communication, 2017 Aug 8).Generally, people living in rural and
380   remote locations also have challenges accessing EMS for urgent conditions including
381   stroke.9 The time taken to transport patients is higher, and distance highly influences
382   whether a patient is taken to a stroke center or not.14 Access to diagnostic services and
383   imaging is not exclusively an issue in rural communities, however. According to Carolyn
384   MacPhail, smaller provinces such as PEI may face similar issues as rural communities in
385   that they lack access to certain technologies, procedures and specialists that other provinces
386   might have, even in the urban setting (Ms. Carolyn MacPhail, Chronic Disease Prevention
387   and Management Manager, Health PEI, Prince Edward Island: personal communication,
388   2017 Sep 27).
390   Access to Stroke Specialists
391   In urban centers, stroke specialists are often available in hospitals, however, they are usually
392   not immediately available in rural centers.18 Carolyn MacPhail noted that overall it can be a
393   challenge to get specialists in smaller provinces like PEI (Ms. Carolyn MacPhail: personal
394   communication, 2017 Sep 27). The specialized expertise required to provide advanced
395   stroke care is generally limited to larger communities and urban areas, and patients living
396   outside these boundaries in the past did not have access to this care.9 Moreover, Dr.
397   Stephen Phillips stated, the low population density in Nova Scotia’s rural settings means
398   hospitals do not manage many stroke patients, and clinicians are therefore less familiar with
399   recognizing stroke symptoms and signs (Dr. Stephen Phillips, Professor of Medicine
400   (Neurology), Dalhousie University, Nova Scotia; Stroke Neurologist, Halifax Infirmary, Nova
401   Scotia: personal communication, 2017 Sep 27). According to Dr. Devin Harris, rural
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402   paramedics in BC may not have as much stroke experience as their urban counterparts,
403   travel times take longer and management within the emergency room (ER) is dependent on
404   local expertise and imaging capabilities (Dr. Devin R. Harris: personal communication, 2017
405   Aug 22).
407   While there have been improvements, according to Dr. Stephen Phillips in Nova Scotia,
408   facilities in urban settings generally have in-house radiologists and 24/7 access to CT
409   scanning and technicians (Dr. Stephen Phillips: personal communication, 2017 Sep 27). Dr.
410   Devin Harris added that urban facilities in BC will also offer neurology services and stroke
411   teams including stroke neurologists and nurses (Dr. Devin R. Harris: personal
412   communication, 2017 Aug 22). Conversely, rural areas may not have a CT scanner staffed
413   at all times and technologists therefore need to be called in during off-hours which may
414   cause further delays in getting a patient scanned. This becomes especially problematic in
415   smaller communities where the expense of a standard CT scanner with the requirement of
416   specialized technicians may not be feasible.19 Moreover, Dr. Stephen Phillips and Lori Latta
417   both noted that in hospitals serving large rural areas, pressure on limited radiology resources
418   means that radiologists may not be available to read a CT image in a timely manner (Dr.
419   Stephen Phillips: personal communication, 2017 Sep 27, Ms. Lori Latta: personal
420   communication, 2017 Nov 17). Pam Ramsay indicated that in BC, this challenge has been
421   mitigated through the creation of Tiers of Service for Stroke. These tiers of service support
422   decisions regarding bypassing of rural and remote patients to a higher level of care (Ms.
423   Pam Ramsay, Provincial Director, Stroke Services BC, Provincial Health Services Authority,
424   British Columbia: personal communication, 2017 Aug 30).

426   While access to CT imaging can be a significant barrier for some areas, one study
427   demonstrated that a portable CT scanner can be used successfully in the evaluation of
428   patients in remote regions that are not within timely reach of stroke experts or do not have
429   available conventional imaging with CT scans.19 Another strategy identified in the literature is
430   the use of mobile stroke units, which are ambulances equipped with point-of-care blood tests
431   and CT imaging and staffed with specially trained nurses, paramedics, and physicians.20 The
432   results from several studies in a meta-analysis reported that the time from symptom onset to
433   treatment with intravenous thrombolytic agents is significantly shorter with patients arriving at
434   hospital by mobile stroke unit compared with patients arriving by ambulance.20
436   Telestroke
437   The use of Telestroke systems enables improved communication and networking to increase
438   access to stroke expertise, regardless of the physical location of the patient.20 One challenge
439   is that Telestroke delivery of care still requires the treating center to complete a CT scan
440   immediately, which is not always feasible due to several issues including the availability of
441   skilled technicians.19 A further challenge to the use of this technology identified by Pam
442   Ramsay was that when a rural or remote community hospital is consulting with a
443   comprehensive stroke centre to determine if a patient is eligible for transfer for endovascular
444   treatment, there may be delays in transmission/availability of CT imaging (multiphase CTA).
445   This imposes undue delay (Ms. Pam Ramsay: personal communication, 2017 Aug 30).

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447   Political
449   The political domain focuses on the distribution of power, assets and interests within a
450   population, as well as the range of organizations involved, their interests and the formal and
451   informal rules that govern interactions between them.11
453   Dr. Stephen Phillips noted that one of the defining characteristics of stroke care is that it cuts
454   across many areas of the health care system including EMS, radiology, neuroradiology,
455   neurology nursing, and the ER, as well as internal medicine, neurology, and neurosurgery
456   (Dr. Stephen Phillips: personal communication, 2017 Sep 27). This can make it challenging
457   to determine who is ultimately responsible and who the decision-maker is not only for patient
458   care but also for system organization (Dr. Stephen Phillips: personal communication, 2017
459   Sep 27).
462   Ethical
464   The ethical domain refers to the concepts of morality, which encompasses beliefs, standards
465   of conduct and principles that guide the behavior of individuals and institutions.11
467   With regards to emergency response, there is an ethical dilemma sometimes posed for rural
468   and remote communities. More specifically, when one in-service ambulance is occupied
469   transporting a patient to a comprehensive stroke center, if there are only a small number of
470   ambulances in a region, this could compromise care for other citizens in that jurisdiction.15
471   Pam Ramsay echoed this notion stating that in BC as part of the Tiers of Service model and
472   stroke bypass protocols, the decision may be to bypass a community facility with limited
473   stroke expertise or imaging capability to a higher level of care facility. In smaller
474   communities, this may result in an ambulance leaving a community that may only have a
475   limited number of ambulances services in the community (Ms. Pam Ramsay: personal
476   communication, 2017 Aug 30). This is compounded in the winter season with variable road
477   conditions. Given this, it is critical that there be partnership with emergency health services
478   in planning for stroke transport (Ms. Pam Ramsay: personal communication, 2017 Aug 30).
480   Another condition was discussed with the emergence of the “opioid crisis” where the BC
481   system was faced with increasing demand for EMS. Again, partnership with emergency
482   health services was critical in ensuring no impact to response times for stroke patient
483   transports (Ms. Pam Ramsay: personal communication, 2017 Aug 30).
485   Domains of Implementation
487   Provider
489   This implementation domain focuses on the characteristics of the individuals adopting and
490   delivering the intervention. This domain includes both the personal attributes, knowledge,
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

491   skills, emotions, motivations, intentions and goals.11 The literature review and consultations
492   pointed towards a few key areas when considering the role of providers with respect to
493   implementation: training and education, guidelines and buy-in, and physician collaboration.
495   Training and Education
496   The largest barrier to stroke training for Canadian physicians, according to Dr. Devin Harris,
497   is the limited time within emergency medicine residency programs devoted to stroke (Dr.
498   Devin R. Harris: personal communication, 2017 Aug 22 ). In one Canadian study, 1% of
499   lecture time was devoted to stroke and TIA within the emergency medicine residency
500   programs, despite neurologic emergencies being 5% of all presenting complaints to
501   emergency rooms.21 The majority of teaching around stroke and TIA is primarily academic,
502   in the form of limited lectures and oral examinations.21
504   Dr. Stephen Phillips pointed to the fact that internists are generally responsible for
505   conducting stroke assessments in regions and facilities in Nova Scotia without neurologists,
506   yet internal medicine residents get relatively little training in neurology (Dr. Stephen Phillips:
507   personal communication, 2017 Sep 27). Dr. Devin Harris remarked that remote outposts in
508   BC may be particularly challenged because these have limited stroke expertise and
509   diagnostic capability. In addition, pre-hospital care is often provided through caregivers (Dr.
510   Devin R. Harris: personal communication, 2017 Aug 22).
512   One way to mitigate this, according to Dr. Patrice Lindsay, is through in-hospital training,
513   regional stroke training, and best practice webinars so that stroke education can be provided
514   not only to physicians but also nurses, rehabilitation experts, technologists and other staff
515   who are part of the stroke continuum (Dr. Patrice Lindsay: personal communication, 2017
516   Sep 12). Dr. Lindsay added that this emphasizes the imperative need to develop strong
517   regional stroke systems of care including the use of technology such as telestroke to support
518   assessment, diagnosis and management decision-making in rural regions (Dr. Patrice
519   Lindsay: personal communication, 2017 Sep 12).
521   Guidelines and Buy-in
522   Clinical practice guidelines can pose a particular challenge to optimizing diagnostic
523   strategies. While there are national guidelines for the diagnosis and treatment of stroke,10
524   specialist physicians may have discipline-specific guidelines, which may not completely align
525   with the Canadian Stroke Best Practice Recommendations.10 Dr. Stephen Phillips felt that
526   this misalignment posed additional challenges for reaching agreement on how to best deliver
527   stroke care (Dr. Stephen Phillips: personal communication, 2017 Sep 27). Patrice Lindsay
528   added that some specialists may not always follow guidelines completely due to the
529   emergent nature of the situation, available resources and local protocols or restrictions, such
530   as not making CTA the routine first line imaging (and performing NCCT only) (Dr. Patrice
531   Lindsay: personal communication, 2017 Sep 12).
533   Buy-in was cited by many interviewed as a common barrier with respect to providers. Dr.
534   Patrice Lindsay and Dr. Stephen Phillips were of the opinion that, regardless of practice
535   guidelines or department policy, some physicians are more committed to and engaged in

      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

536   stroke care than others. (Dr. Patrice Lindsay: personal communication, 2017 Sep 12, Dr.
537   Stephen Phillips: personal communication, 2017 Sep 27). Carolyn MacPhail pointed to the
538   importance of family physicians and nurse practitioners also needing to buy-into the value of
539   having a stroke unit although the majority of persons with stroke spend at least part of their
540   stay on the provincial stroke unit and some family physicians in PEI do not yet utilize
541   established protocols (Ms. Carolyn MacPhail: personal communication, 2017 Sep 27).
543   Dr. Stephen Phillips added that there are still physicians in Canada who are not supportive
544   of tPA (tissue plasminogen activator, a treatment for stroke), which slows down buy-in for
545   stroke care improvements (Dr. Stephen Phillips: personal communication, 2017 Sep 27). In
546   Nova Scotia, efforts to enhance stroke care are continuing more than a decade after the
547   provincial government committed dedicated funding to it. An enabler identified by both Dr.
548   Devin Harris and Lori Latta was the use of physician champions to implement protocols and
549   promote guideline uptake in both BC and Saskatchewan (Dr. Devin R. Harris: personal
550   communication, 2017 Aug 22, Ms. Lori Latta: personal communication, 2017 Nov 17). For
551   Carolyn MacPhail this included bringing together physician groups including ER physicians
552   and radiology peers about the use of protocols and benefits of CTA, for example (Ms.
553   Carolyn MacPhail: personal communication, 2017 Sep 27). Dr. Phillips added that in each
554   health district in Nova Scotia, they appointed and provided some salary support for a lead
555   stroke physician - family physician or internist – who took responsibility for helping build the
556   local stroke program, and this turned out to be a key component of their implementation
557   success (Dr. Stephen Phillips: personal communication, 2017 Sep 27).
559   Physician Collaboration
560   There was general agreement among those interviewed that collaboration between
561   physicians across radiology, neurology and emergency was key to a successful stroke
562   program. Both Dr. Eddy Lang and Dr. Patrice Lindsay highlighted the importance of these
563   specialties coming together to find a common approach and working towards better
564   integration in order to provide the best care possible (Dr. Eddy Lang: personal
565   communication, 2017 Aug 8, Dr. Patrice Lindsay: personal communication, 2017 Sep 12).
566   There was agreement between Jeremy Measham in PEI and Dr. Eddy Lang in Alberta that
567   there is room for improvement in communication between ER physicians, neurologists and
568   radiologists and understanding who is ultimately the decision-maker for the stroke patient
569   presenting to the ER (Mr. Jeremy Measham, Special Projects Coordinator, Island EMS,
570   Prince Edward Island: personal communication, 2017 Sep 26; Dr. Eddy Lang: personal
571   communication, 2017 Aug 8).
573   Patient
575   The additional patient domain was also considered, which combines socio-cultural, socio-
576   economic, and epidemiological components of the context domains of the INTEGRATE-HTA
577   framework.
578   Stroke often renders patients incapable of seeking help themselves, leaving bystanders or
579   family members responsible for contacting emergency services.17 Approximately two-thirds
580   of all patients who seek acute care for stroke in Canada arrive at the ER by ambulance.10
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

581   The greatest proportion of patients who received timely neuroimaging were those who
582   presented to the ER within 30 to 60 minutes after symptom onset.17
583   Stroke does not uniformly engender a sense of urgency because it does not usually cause
584   pain and many people do not know how to recognize stroke in another person and to seek
585   help.14 As such, people need to be aware of the signs of stroke and contact EMS without
586   delay to maximize eligibility for these time-sensitive treatments.9 Dr. Devin Harris
587   emphasized the need for patient and family awareness as to the signs and symptoms of
588   stroke which can be difficult to recognize, leading to people arriving too late to the ER.
589   Stroke may present with significant neurological deficits and, at other times, with headaches
590   or vision problems, so awareness is key (Dr. Devin R. Harris: personal communication, 2017
591   Aug 22). Pam Ramsay and Dr. Patrice Lindsay both referenced the Heart and Stroke
592   Foundation of Canada’s FAST campaign as being an enabler to patient education (Ms. Pam
593   Ramsay: personal communication, 2017 Aug 30, Dr. Patrice Lindsay: personal
594   communication, 2017 Sep 12).33 Dr. Patrice Lindsay noted that Canadian patients today are
595   much more informed when it comes to their health and their families are more aware about
596   when and how to act when faced with a potential stroke, although there is still much work to
597   be done (Dr. Patrice Lindsay: personal communication, 2017 Sep 12).
599   Organization and Structure
601   This domain comprises the organizational policies, guidelines and practices as well as
602   culture and climate that reside within an organization and on different levels such as the
603   organization as a whole, units, and teams through which an intervention is delivered.
604   Therefore, constructs such as team dynamics, leadership, supervision and guidance are
605   also comprised.11
607   The literature review and consultations highlighted the following organization and structure
608   enablers and barriers with respect to implementation: pre-arrival notification and bypass,
609   coordination of care, and culture.
611   Pre-arrival Notification and Bypass
612   Among patients with acute ischemic stroke, transport by EMS has been associated with
613   earlier arrival and faster emergency department evaluations – these benefits stem, at least in
614   part, from pre-arrival activation of stroke teams because of hospital pre-notification by EMS
615   and bypass protocols.22
617   Pre-arrival notification to hospital has been found to be extremely beneficial in PEI as
618   described by Jeremy Measham (Mr. Jeremy Measham: personal communication, 2017 Sep
619   26). Typical intake protocols for when patients present to the ER, in his opinion, simply
620   cause delays and lengthen the door-to-CT time. Instead, the ER nurse manager and
621   physician in PEI will be notified by EMS of the incoming stroke patient and will meet the
622   patient at the doors of ER and quickly triage and decide if they should go to CT rather than
623   finding a bed in the ER to wait in. These patients will thereby bypass the ER and be taken
624   directly to the CT scanner accompanied by the paramedic and then the ER physician or

      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

625   stroke specialist will see the patient later in the ER to decide on next steps (Mr. Jeremy
626   Measham: personal communication, 2017 Sep 26).
628   Guideline-recommended prehospital practices have been demonstrated to improve the
629   efficiency of in-hospital care for stroke patients.23 One study suggests that hospital pre-
630   notification is associated with improved stroke response as measured by door-to-evaluation
631   times and the rate and speed of tPA delivery.23 Another study found that EMS-recognized
632   strokes had faster door-to-CT times and transportation by EMS is an important predictor of
633   improved in-hospital stroke response and use of tPA for patients with acute ischemic
634   stroke.22 Findings from the North Carolina Stroke Care Collaborative showed that arrival by
635   EMS (versus private transport) was associated with faster access to brain imaging and faster
636   interpretation of these images.9
638   According to Dr. Patrice Lindsay, organizational relationships and partnerships with EMS are
639   key enablers with a common understanding that paramedics are not merely transporters but
640   are experts trained to recognize the signs of stroke and take appropriate actions (Dr. Patrice
641   Lindsay: personal communication, 2017 Sep 12). Dr. Stephen Phillips and Pam Ramsay
642   added that because paramedics are at the front lines, they are instrumental in
643   operationalizing bypass protocols as demonstrated in both Nova Scotia and BC respectively
644   (Dr. Stephen Phillips: personal communication, 2017 Sep 27, Ms. Pam Ramsay: personal
645   communication, 2017 Aug 30).
647   Jeremy Measham described how stroke system stakeholders in the province of PEI have
648   developed a diversion policy to divert stroke patients in ambulance from minor hospitals that
649   do not have CT to sites that have these technologies. Because the island’s EMS is
650   centralized, if an ambulance is moved away from one community, another will be moved to
651   fill the gap (Mr. Jeremy Measham: personal communication, 2017 Sep 26).
653   Coordination of Care
654   Although an ideal system might see all patients receiving care at specialized stroke centers,
655   this may be difficult to achieve in large, geographically diverse jurisdictions.8 Coordinated
656   systems of stroke care have been established in many provinces which include bypass
657   protocols for paramedics and the use of Telestroke modalities to access specialists at large
658   urban centers for consultation and to support intravenous tPA administration.10 Dr. Devin
659   Harris added that urban hospitals in BC tend to have in place structured protocols,
660   guidelines, imaging equipment, and overall access to endovascular therapy and stroke units
661   which rural facilities typically do not (Dr. Devin R. Harris: personal communication, 2017 Aug
662   22).
664   The overall coordination of stroke care is a challenge identified by Lori Latta (Ms. Lori Latta:
665   personal communication, 2017 Nov 17). Nurse coordination or stroke team coordination, is
666   vital to raising profile of stroke and ensuring that standardized order sets for care and
667   administration of treatments adhered to (Ms. Lori Latta: personal communication, 2017 Nov
668   17).

      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

670   Culture
671   From a cultural perspective, Dr. Devin Harris believes that there has been a paradigm shift
672   within the medical community when it comes to stroke, stating “At one time, we did not think
673   that stroke was treatable and preventable. Now we know it is treatable and preventable and
674   this changes our approach to how we deal with patients. There is still room for improvement”
675   (Dr. Devin R. Harris: personal communication, 2017 Aug 22). Dr. Eddy Lang added that, “It
676   was only a decade ago that most urban hospitals were operating their imaging machines for
677   fixed hours but now we are seeing an evolution in thinking to recognize that neurology
678   emergencies can happen at any hour of the day and so imaging need to be available 24/7”
679   (Dr. Eddy Lang: personal communication, 2017 Aug 8).
681   Funding
683   The domain of funding relates to short-term or longer-term funding mechanisms by
684   governmental, non-governmental, private sector and philanthropic organizations used to
685   implement an intervention.11
687   Dr. Devin Harris highlighted that stroke is a continuum disorder, so the funding needed for it
688   in his province of BC does not usually align with the necessary silos (ER, radiology,
689   neurology, etc.) which generally have different reporting structures (Dr. Devin R. Harris:
690   personal communication, 2017 Aug 22). With shrinking budgets and hospitals often required
691   to curb spending, finding additional funds available for stroke services and costly imaging
692   technologies is challenging (Dr. Devin R. Harris: personal communication, 2017 Aug 22).
693   One study reviewed found that patients in the US used significantly more imaging resources
694   than patients in Canada, where capacity is restricted by centralized provincial budgets.26
696   Pam Ramsay noted that capital investments are always a challenge in the acute care setting
697   adding that we must be mindful of the capabilities of CT scanners in small communities in
698   BC and that some may be in need of upgrading (Ms. Pam Ramsay: personal
699   communication, 2017 Aug 30). Pam Ramsay and Jeremy Measham in PEI both stated that
700   operational investments (human resources) are another barrier with the need for staff
701   available to respond to stroke cases 24/7 including specialist physicians and imaging
702   technicians (Ms. Pam Ramsay: personal communication, 2017 Aug 30, Mr. Jeremy
703   Measham: personal communication, 2017 Sep 26).
705   One article reviewed noted that a limitation in addressing stroke patients is that 24 hour CT
706   scanning may not be possible at all acute sites due to lack of resources, and patient transfer
707   to larger centers can result in precious time loss and may not always be possible for patients
708   with unstable conditions.19
710   This becomes especially important in smaller communities where the expense of a standard
711   CT scanner with the requirement of specialized technicians may not be feasible.19 Dr. Devin
712   Harris and Dr. Patrice Lindsay echoed this opinion and added that funding for personnel to
713   operate diagnostic imaging equipment (CT scanners) 24 hours a day, seven days a week is
714   a challenge for many Canadian facilities including those in urban settings (Dr. Patrice

      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

715   Lindsay: personal communication, 2017 Sep 12, Dr. Devin R. Harris: personal
716   communication, 2017 Aug 22).
718   In some jurisdictions another challenge exists where some people avoid calling EMS
719   because of the fees associated with the ambulance. From Carolyn MacPhail’s perspective,
720   some people in PEI believe that they can get themselves faster to hospital than EMS and
721   without the associated cost (Ms. Carolyn MacPhail: personal communication, 2017 Sep
722   27).34 Given the importance of minimizing the door-to-treatment time for patients with
723   suspected stroke, it is important that people understand the specialized training that EMS
724   personnel have in responding to stroke patients and not merely as ambulance transport.
725   Moreover, stroke protocols are put in place to ensure that treatment occurs in the right place
726   and in a timely manner (Ms. Carolyn MacPhail: personal communication, 2017 Sep 27).
728   Policy
730   According to INTEGRATE-HTA, the policy domain comprises policy measures and
731   processes of government, public, private or other organizations directly concerning or
732   indirectly influencing the implementation of an intervention.11
734   There is much agreement in the literature and among most interviewed that one of the
735   biggest enablers to managing ischemic stroke is the use of standardized protocols in both
736   urban and rural/remote settings. One article underscored that effective and standardized
737   imaging protocols are necessary for clinical decision making.25 In BC, Dr. Devin Harris
738   reports that a key enabler for his facility has been the use of standardized stroke protocols
739   (Dr. Devin R. Harris: personal communication, 2017 Aug 22).
741   Dr. Patrice Lindsay added that protocols facilitate the process for paramedics in more urban
742   settings as they are often trained and can identify the signs of stroke (Dr. Patrice Lindsay:
743   personal communication, 2017 Sep 12). Pam Ramsay in BC added that a policy around
744   bypass is also necessary, particularly when a decision needs to be made regarding air
745   versus ground transport of stroke patients (Ms. Pam Ramsay: personal communication,
746   2017 Aug 30). This type of system coordination requires that hospitals work with EMS which,
747   according to Trish Helm-Neima, they are doing in PEI (Ms. Trish Helm-Neima, Provincial
748   Stroke Coordinator, Health PEI, Prince Edward Island: personal communication, 2017 Sep
749   27). One article emphasized that coordinated systems of care and ambulance bypass
750   agreements must continue to evolve to ensure maximal access to hyper acute stroke
751   services.9
753   In BC, an example of a policy that potentiated a barrier to implementing “best practice stroke
754   care” was described by Pam Ramsay (Ms. Pam Ramsay: personal communication, 2017
755   Aug 30). In an effort to reduce wait times and backlogs in the ER, patients were being
756   transferred out of the ER into the first available hospital bed (in-patient) as quickly as
757   possible. Although patient focused, this might mean that a patient with a stroke could be
758   transferred to a bed other than the most appropriate stroke unit bed. Efforts are required to

      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

759   harmonize competing policies/guidelines (Ms. Pam Ramsay: personal communication, 2017
760   Aug 30).
762   One key policy change that is expected to drive change in the stroke system is the
763   mandating to collect key data elements in a jurisdiction. Pam Ramsay noted that in BC all
764   health authorities are now recording stroke information in the discharge abstract database
765   (DAD) to measure time-to-CT and transfer time-to-stroke unit for example (Ms. Pam
766   Ramsay: personal communication, 2017 Aug 30).
768   Socio-economic, Socio-cultural, Legal and Epidemiological
770   The consultations and literature search together did not yield any articles which addressed
771   the INTEGRATE-HTA domains of socio-economic, socio-cultural, legal and epidemiological.
772   All other domains are described with respect to challenges and enablers of implementation
774   Limitations
775   The findings of this environmental scan aim to present an overview of examples and current
776   information regarding the diagnostic imaging for ischemic stroke in the emergency room
777   setting and are not intended to provide a comprehensive review of the topic. The results are
778   based on a limited, non-systematic literature search and consultations with nine
779   stakeholders. While there was representation from BC, Alberta, Saskatchewan, Ontario,
780   Nova Scotia and PEI not all jurisdictions responded to our request for an interview and some
781   respondents were only able to speak on behalf of a single site or organization and not the
782   jurisdiction’s health care system as a whole. Moreover, opinions and perspectives provided
783   as part of the targeted stakeholder consultations may not be representative of the views of
784   all stakeholders across Canadian jurisdictions.
785   The literature search did not identify studies pertaining to many aspects of issues relating to
786   implementation, or aspects of the integrate-HTA framework. There was a lack of information
787   regarding the epidemiology, socio-economic status, political, policy, socio-cultural and legal
788   domains of integrate-HTA.
789   There were also limitations in the data used from the CMII database. The setting of “urban”,
790   “rural”, or “remote” were self-reported by the individual who filled out the survey and were not
791   guided by a specific definition of these settings. This means that the categorization by setting
792   may not be completely accurate. Additionally, 39.9% of respondents reported on the setting
793   of their site, thus some information may not have been captured in the survey, and therefore
794   not reported.
796   Conclusion
798   The Environmental Scan included a review of the literature and targeted consultations with
799   stakeholders from British Columbia, Alberta, Saskatchewan, Ontario, Nova Scotia and
800   Prince Edward Island and included both health care professionals and health system
801   administrators.
      CADTH ENVIRONMENTAL SCAN: Diagnostic Imaging of Ischemic Stroke in the Emergency Room
      Setting: Implementation Considerations

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