Keywords
Ambulance times; emergency care; COVID-19 pandemic; prehospital; protocol; stroke; systematic review; transient ischaemic attack.
This article is included in the Coronavirus (COVID-19) collection.
Ambulance times; emergency care; COVID-19 pandemic; prehospital; protocol; stroke; systematic review; transient ischaemic attack.
The protocol has been revised following peer review. We have now made it clear in the title and throughout the article that the review is focusing on adult patients. We have added information to the introduction explaining the relevance of ambulance times for this population, the chain of recovery for acute ischaemic stroke and why stroke/transient ischaemic attacks (TIA) are particularly vulnerable to pressures on the healthcare system. Also, we have justified the inclusion of both stroke and TIAs in this review, the use of an initial search and using both the JBI critical appraisal tools and the GRADE tool. We have clarified that we are looking at call taker classification in this review and that papers need to include at least one of the specific time periods or information on emergency call volume for stroke/TIA to be considered for inclusion. We have added that we will be conducting both forward and backward searching of reference lists. We have clarified the process of data extraction and will now also collect information on the emergency dispatch system, if available. In response to comments on the sub-group analysis, we have provided information on the categorisation of factors, such as location, as much as possible. Also, we have added further information on the potential implications of this review in increasing understanding of healthcare system resilience in response to crises. Also, we have justified the use of the ambulance times included in the protocol. Additionally, a new table has been added, the title has been slightly amended, and three new authors have been added.
See the authors' detailed response to the review by Eithne Sexton
See the authors' detailed response to the review by Janet E. Bray
See the authors' detailed response to the review by Graham McClelland
The COVID-19 pandemic was a “shock” to the health system, globally1. COVID-19 was declared a pandemic by the Director-General of the WHO at the media briefing on 11 March 20202. Consequently, it is reported that the pandemic affected non-COVID healthcare in many countries3,4. Public health guidelines were introduced in an effort to manage the pandemic, including travel restrictions and stay at home orders. These interventions may have impacted on healthcare seeking behaviours. Furthermore, the healthcare workforce was directly impacted through sickness and periods of isolation/restriction of movements for cases and contacts5.
Globally, delayed, and reduced admissions for non-COVID related care have been linked to increased mortality and morbidity6,7. Reports from multiple countries indicated that calls to emergency medical services vastly increased over the course of the pandemic8. As a result, further pressure was put on prehospital emergency services8.
The prehospital phase of healthcare is defined in a World Health Organisation report as the period before arrival at a hospital, clinic, and other fixed healthcare setting9. Prehospital care generally includes the provision of care by emergency medical service providers such as emergency medical dispatchers, emergency medical responders, emergency medical technicians, and paramedics10. As ambulance times are internationally recognised key performance indicators for prehospital emergency care they will be used as the primary outcome of interest in this review11. Ambulance times are relevant to prehospital stroke/transient ischaemic attack (TIA) care as the role of the emergency medical services in this context involves prompt transport to secondary care specialists. As treatment strategies for stroke/TIA are time-dependent, it is important to minimise time delays in the prehospital phase of care12.
In 2019, stroke was the second leading cause of disability-adjusted life-years (DALYs) globally, in the 50–74 years and 75+ years age groups13. Up to one in three strokes are preceded by a TIA, with approximately 50% of these occurring within a year after the TIA14. Stroke and TIA can have similar presentations and are being included in this review as it is focusing on information provided to the call taker by the caller before clinical assessment has been performed. Also, within the timeframe in which prehospital care practitioners care for the patient it may not be possible to differentiate between symptoms of a stroke/TIA. Furthermore, some dispatch systems, such as AMPDS15, have the same code for stroke and TIA.
Stroke is a medical emergency and requires immediate evaluation, confirmation of diagnosis and treatment in order to prevent brain damage16. The acute ischaemic stroke chain of recovery involves recognition (of symptoms), reaction (emergency services alerted), response (medical assessment), reveal (brain imaging), and Rx (treatment initiation)17. Early diagnosis and treatment are also imperative for TIA, to reduce mortality and risk of stroke18. Stroke and TIA could be considered as particularly vulnerable to pressures on health system care delivery or changes in care seeking behaviours by patients. Due to the time-sensitive nature of stroke/TIA intervention it is imperative that stroke/TIA survivors present to hospital as soon as possible after symptoms develop16. An increased volume of emergency calls may mean that not as many call takers or ambulances are available. Furthermore, patients may have been hesitant to call an ambulance during COVID-19 due to fear of contracting the disease8. Recent preliminary evidence suggests that stroke and cardiac arrest were the emergency cases most affected by the COVID-19 pandemic8.
There has been a global decrease in the number of patients seeking medical care for stroke and TIA during the pandemic19–21. Thus, COVID-19 has potentially had a disruptive effect on the stroke chain of survival7,22. It has been reported that stroke admissions in Southern Europe have fallen by 25% over the pandemic period21. Furthermore, the number of emergency medical service calls dispatched to stroke dropped, and a 30-minute delay in response times have been reported, in this region21. One narrative review stated that the suggested disruption in the emergency stroke care pathway due to the COVID-19 pandemic has resulted in a global surge of prehospital mortality8.
Research in this area has previously focused on the nature and volume of emergency medical service calls, prehospital stroke triage and acute stroke hospital-based care, during the COVID-19 pandemic8,23–25. However, it is still largely unknown what impacts on prehospital emergency care for stroke and TIA were seen and how they varied in different countries, with different approaches to the management of the pandemic and different underlying healthcare systems. Thus, this systematic review and meta-analysis aims to summarize the existing international evidence on the impact of the COVID-19 pandemic on prehospital emergency care for adult patients with stroke or TIA and estimate the ambulance times and emergency call volumes for stroke/TIA.
This protocol was developed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols Checklist (PRISMA-P)26. The proposed systematic review and meta-analysis will follow the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines27. This review is registered on PROSPERO (registration number CRD42022315260).
To summarize the existing international evidence on the impact of the COVID-19 pandemic on prehospital emergency care for adult patients with stroke or TIA and estimate the ambulance response times and emergency call volumes for stroke/TIA.
Primary outcomes: activation time, response time, patient care time.
Secondary outcome: emergency medical services call volume for stroke/TIA.
Ambulance times include three main time periods in the time from receipt of the emergency call by the call centre operator to the patient arriving at the hospital28. “Activation time “covers the period from receipt of the call to mobilisation of a fully crewed emergency ambulance28. “Response time” covers the period from receipt of call to the arrival of the ambulance at the scene of the emergency28. “Patient care time” refers to the time from arrival of an ambulance crew at the scene to arrival at hospital28. In this review “patient care time” 24 will include time spent on scene and the transport to hospital time28. The terminology used to describe these three key time periods can vary between countries and publications8,28. Regardless of the term used, these three distinct periods of time are a key focus of this review. Thus, the search terms of the review relating to emergency care have remained broad to encompass as many variations as possible. The time periods chosen are due to clinical significance and previous inclusion in ambulance time-related studies. Due to international variation in terminology and definitions, a standardised definition needed to be used. Members of the ambulance service are advising on this task.
Inclusion criteria
Table 1 details full inclusion and exclusion criteria and justifications for each. This systematic review will include:
● Quantitative studies where prehospital care for adult stroke/TIA patients was compared before and during the COVID-19 pandemic.
● Stroke/TIA diagnosis does not have to be confirmed at hospital level. Due to the context of this study stroke/TIA can be suspected (based on symptoms given to call taker) or working diagnosis after review by an emergency medical services team. A study will not be excluded based on the definition of stroke/TIA diagnosis. However, if available in the study, whether the stroke/TIA was suspected or confirmed will be outlined in the review.
● Studies need to include data on ambulance times or stroke/TIA emergency call volumes in order to be considered for inclusion. A study needs to include data on at least one of: activation time, ambulance response time or patient care time to be eligible for inclusion. Regardless of the terminology used in a particular study, if data are available on any of these three time periods of interest the study is eligible for inclusion.
● Calls identified by the call taker as suspected stroke/TIA will be included and if the data are available these calls will be put in context of calls made to the wider EMS system.
● Primary, peer – reviewed studies in any language.
Exclusion criteria
Initial search29,30: ProQuest and PubMed will be used to search for relevant articles. The librarian recommended these databases due to the context of the study, and the range of articles available on these databases. Words and phrases found in the title, abstract, and index of these papers will inform the final search strategy.
Second search: Using the identified search terms a formal search of Embase (Elsevier), ProQuest, PubMed, Scopus (Elsevier), Web of Science (Clarivate) and Wiley will be conducted. These searchers will be included in the final PRISMA flow chart27.
Reference list search: Backward and forward citation searching will be conducted on all included studies. The Peer Review of Electronic Search Strategies (PRESS) will be used to evaluate the search strategy31,32. The number of studies identified in the reference list screening will be included in the PRISMA flow chart27.
An expert university librarian was involved in the selection of initial search terms and databases for this protocol. The librarian has also advised on refining and designing the final search strategy. They have advised on the most appropriate Medical Subject Headings (MeSH) terms for the search strategy and offered input into adapting these terms for the selected databases. Table 2 details a sample initial search strategy for the PubMed database. Table 3 details the final search strategy for the PubMed database.
Identified citations will be collated and uploaded into Endnote™ 20 (Clarivate Analytics, PA, USA)) and duplicates removed. Titles and abstracts of published literature will be imported into Covidence (https://www.covidence.org/)., and screened using the software, by two independent reviewers (EB and JA) for assessment against the inclusion/exclusion criteria for the review. Potentially relevant sources will be retrieved in full, and their citation details imported into Covidence. The full text of selected citations will be assessed in detail against the inclusion criteria by EB and JA.
Reasons for exclusion of sources of evidence at full text that do not meet the inclusion criteria will be recorded and reported in the systematic review. Any disagreements that arise between the reviewers at each stage of the selection process will be resolved through discussion between EB and JA. If necessary, any disagreement will then be referred to a third reviewer VMc and resolved by consensus.
The results of the search and the study inclusion process will be reported in full in the final systematic review and presented in PRISMA flow diagram27.
Data extraction and management
A standardised extraction form has been composed using Microsoft Word (version 2102), which fulfils the eligibility criteria (Table 1). This template has been compiled based on the aim and objective of the review and what data will be required to effectively report the results of this review.
EB will extract the data from the included papers. JA will check a random sample of 20% of these studies for accuracy of data extraction. Finalising the data extraction form may be an iterative process, and modification or revision may occur after piloting. Any disagreements will be resolved upon discussion with VMc. This process ensures transparency and clarity in the process of data extraction. The categories below will be included in the first version of the form, which can be found in Table 4. Any modifications to the existing data extraction form will be reported in the systematic review.
The appropriate Joanna Briggs Institute (JBI) Critical Appraisal tool33 will be used to appraise the quality of each included study. The JBI tools will be used as it is anticipated that eligible studies will be cohort studies or quasi-experimental studies. JBI offers a critical appraisal tool for both. The JBI checklist offers a series of questions to which “Yes”, “No”, “Unclear” and “Not applicable” are the provided answers. These checklists will be used to assess risk of bias in individual studies. The GRADE34 tool is being used to assess the overall quality of cumulative evidence. Two reviewers (EB and JA) will independently assess study quality. If necessary, discrepancies will be resolved by VMc.
A PRISMA flow diagram27 will be included in the review to illustrate the study selection process, and also will provide a rationale for excluding studies. Tables displaying study characteristics and quality assessment will be included. Forest plots will be used to present pooled estimates. If a study is eligible for inclusion in the review but does not include sufficient data for inclusion in the meta-analysis the corresponding study authors will be contacted for access to raw data, in the first instance. If raw data cannot be obtained, the findings of the relevant studies will be included in a separate table or narratively presented.
Meta-analysis will be conducted, where the data allows, to calculate pooled estimates of the difference between ambulance times (time of call to ambulance being dispatched (activation time), time from ambulance being dispatched to arrival at the incident location (response time), and time spent on scene and from the incident location to the hospital (patient care time) and call volumes for stroke/TIA before and during the COVID-19 pandemic.
Where heterogeneity is low (I2 value of less than 50%) a fixed-effects model will be used and where heterogeneity is high (I2 value of 50% or more) a random-effects model will be used, according to the Cochrane Handbook criteria35.
The following subgroup/sensitivity analyses will be performed using RevMan 5.4 where the data allow:
1. According to location. (Classification will be determined once papers are selected)
2. According to income level of country. (Determined by World Bank Classification36)
3. According to study quality. (Determined by appropriate JBI critical appraisal tool33)
4. According to COVID-19 case numbers/hospitalisations in the country/area at the time of the study. (John Hopkins Coronavirus Resource Centre and Oxford Martin School data will be used37,38)
5. According to the number of weeks since the World Health Organisation categorized COVID-19 as a pandemic. (This was stated by the Director-General of the WHO at the media briefing on 11 March 20202)
6. According to stroke/TIA diagnosis (suspected stroke/TIA, working diagnosis after review by emergency medical services, or hospital confirmed diagnosis)
A funnel plot will be used to assess publication bias if ten or more studies are included in the meta-analysis. Any asymmetry of the funnel plot arising from publication bias will be addressed using the trim and fill method39.
If any further subgroup/sensitivity analyses need to be carried out during the meta-analysis process, these will be identified as post hoc analyses.
The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation guidelines (GRADE)34.
A Consultant Neurologist (AM) aided in the development of the research question for this review. AM will be asked about resources on the review topic that might not be identified through the searching of databases, and references. The consultant neurologist will help with dissemination of review results and offer suggestions on how best to disseminate the results of the review to the medical community. Members of the Irish National Ambulance Service Clinical Directorate advised on terminology and clinical significance of time periods, in this protocol. They will also be involved throughout the systematic review and will offer suggestions on how to best disseminate the results of the review to the prehospital emergency care community.
Patient and public involvement (PPI) is described in this protocol and will be described in the systematic review using the GRIPP 2 checklist (short version)40.
A PPI panel of 5 stroke survivors (2 female, 3 male) from a stroke support group were involved in the development of this protocol and subsequent review from an early stage. The PPI panel were consulted on this protocol by means of two face-to-face meetings. PPI contributors were involved in this protocol to advise on development of the research question, which stakeholders to target for involvement in the review, possible search terms, terminology surrounding stroke survivors and their research priorities.
The PPI members emphasised that they believe that the period from onset of symptoms to arrival at hospital was the most important part of the care pathway. They were asked to advise on preferred terminology around the term “stroke survivor” or “stroke patient” and any colloquial terms used for stroke or TIA. Also, they were asked what they felt would be important to know about the impact of the COVID-19 pandemic on prehospital emergency care for those with a stroke/TIA during the COVID-19 pandemic.
As a result, the research question focuses on prehospital emergency care for those with stroke/TIA. PPI had a very positive effect on this protocol41. The PPI contributors used their lived experience to highlight key issues of importance and aspects of stroke care they felt could have been affected by the COVID-19 pandemic. The PPI panel prefer the term “stroke survivor” to refer to those who had a stroke. Thus, where possible this terminology will be used in outreach and dissemination of the review results, especially that targeted towards the lay population.
This group of PPI contributors will also be involved in interpreting the results of this review to identify gaps and in the dissemination of the results.
This systematic review and meta-analysis will summarise existing evidence investigating the impact of the COVID-19 pandemic on prehospital emergency care for those with stroke/TIA. This work may also influence policy guidelines and future research on prehospital management of non-communicable diseases during a pandemic, and prehospital care more broadly. The results may also inform our understanding of healthcare system resilience in response to crises on a broader level. The findings of this review will be disseminated through peer and public presentations, conferences, a policy brief for relevant clinical programmes (stroke and emergency care) and a peer-reviewed journal.
The protocol was registered prospectively with Prospero (registration number CRD42022315260).
Search strategies were confirmed, stakeholders consulted, and title/abstract screening started at the time of publication of this version of the protocol.
Ethical approval is not required for a systematic review.
No data are associated with this article.
Burton E: Conceptualization, Methodology, writing – Original Draft Preparation, writing – Review & Editing; Aladkhen J: Writing – Review & Editing, second reviewer; O’Donnell C; Writing – Review & Editing; Masterson S; Writing – Review & Editing; McCarthy V: Supervision, writing – Review & Editing, second reviewer; Merwick A: Conceptualization, writing – Review & Editing Merwick A: Writing – Review & Editing Kearney PM: Supervision, writing – Review & Editing Buckley CM: Supervision, Writing – Review & Editing
Firstly, we would like to thank Ms. Virginia Conrick, Liaison Librarian, University College Cork, for her help and support with designing and refining the search strategy for this review. Secondly, thank you to Dr. Emmy Racine, and Dr. Oonagh Meade for their guidance and support with involving Patient and Public Involvement contributors in this review. Also, to Ms. Nikolett Warner, who reviewed the section on Patient and Public Involvement in this protocol. Thirdly, thanks to the Patient and Public Involvement contributors; Liam Kelleher, Ann Desmond, Ann Broderick, Martin Kaye and Michael Smithers from the Cork Stroke Support Group for aiding in the development of the research questions, discussing their priorities for immediate care after stroke, and offering guidance on dissemination of review results and terminology surrounding stroke survivors. This review is to contribute towards the doctoral degree of EB.
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Stroke epidemiology; epidemiological modelling; health services research
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Prehosptial
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Prehospital care and stroke
Is the rationale for, and objectives of, the study clearly described?
Yes
Is the study design appropriate for the research question?
Yes
Are sufficient details of the methods provided to allow replication by others?
Yes
Are the datasets clearly presented in a useable and accessible format?
Not applicable
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Prehosptial
Is the rationale for, and objectives of, the study clearly described?
Yes
Is the study design appropriate for the research question?
Yes
Are sufficient details of the methods provided to allow replication by others?
Partly
Are the datasets clearly presented in a useable and accessible format?
Not applicable
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Stroke epidemiology; epidemiological modelling; health services research
Is the rationale for, and objectives of, the study clearly described?
Partly
Is the study design appropriate for the research question?
Yes
Are sufficient details of the methods provided to allow replication by others?
Yes
Are the datasets clearly presented in a useable and accessible format?
Not applicable
Competing Interests: Publications and ongoing research in prehospital stroke care.
Reviewer Expertise: Prehospital care and stroke
Alongside their report, reviewers assign a status to the article:
Invited Reviewers | |||
---|---|---|---|
1 | 2 | 3 | |
Version 2 (revision) 22 Jun 22 |
read | read | read |
Version 1 25 Mar 22 |
read | read | read |
Provide sufficient details of any financial or non-financial competing interests to enable users to assess whether your comments might lead a reasonable person to question your impartiality. Consider the following examples, but note that this is not an exhaustive list:
Sign up for content alerts and receive a weekly or monthly email with all newly published articles
Register with HRB Open Research
Already registered? Sign in
Submission to HRB Open Research is open to all HRB grantholders or people working on a HRB-funded/co-funded grant on or since 1 January 2017. Sign up for information about developments, publishing and publications from HRB Open Research.
We'll keep you updated on any major new updates to HRB Open Research
The email address should be the one you originally registered with F1000.
You registered with F1000 via Google, so we cannot reset your password.
To sign in, please click here.
If you still need help with your Google account password, please click here.
You registered with F1000 via Facebook, so we cannot reset your password.
To sign in, please click here.
If you still need help with your Facebook account password, please click here.
If your email address is registered with us, we will email you instructions to reset your password.
If you think you should have received this email but it has not arrived, please check your spam filters and/or contact for further assistance.
Comments on this article Comments (0)