Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. No Task Force members or other authors were recused from the discussion as they declared a conflict of interest.
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: Bibiana Metelmann, Camilla Metelmann, Sebastian Schnaubelt, and Robert Greif are authors of one of the analyzed publications. Robert Greif is the ERC Director of Guidelines and ILCOR; the ILCOR Task force Education, Implementation, and Teams chair, and member of the editorial board of Resuscitation Plus.
Task Force Synthesis Citation
Sebastian Schnaubelt, Sabine Nabecker, Alexander Olaussen, Andrea Cortegiani, Cristian Abelairas-Gomez, Kathryn Eastwood, Robert Greif. Terminology for individuals or teams attending patients in cardiac arrest Force Synthesis of a Scoping Review [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Education, Implementation and Teams Task Force, 2025 September 15. Available from: http://ilcor.org
Methodological Preamble
The continuous evidence evaluation process started with a scoping review on the terminology used to describe individuals or teams attending patients in cardiac arrest. The review was conducted by the ILCOR Education, Implementation and Teams Task Force, supported by external experts. Evidence for all settings (out-of-hospital and in-hospital, adult and pediatric) was sought and synthesized in accordance with ILCOR guidance and PRISMA-ScR methodology.
Scoping Review
Webmaster to insert the Scoping Review citation and link to Pubmed using this format when/if it is available.
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: All individuals and teams attending patients with cardiac arrest of any age in any setting (lay persons or healthcare professionals, witnesses or dispatched responders).
Intervention: Terms and definitions used to describe such individuals or teams.
Comparators: Not applicable (descriptive scoping review).
Outcomes: Terms and definitions
Study Designs: All types of published peer-reviewed literature (RCTs, observational studies, reviews, consensus papers, commentaries, editorials). Excluded were articles without explicit definitions, other emergencies than resuscitation, or the simple use of terms without explanation.
Timeframe: All from inception until 06/2025.
Search Strategies
We searched MEDLINE (Ovid), Embase (Ovid), Web of Science (Clarivate), and Scopus (Elsevier) from inception to last updated on 5 June 2025. The search strategy was developed using input from an ILCOR Task Force survey including the Task Forces BLS, ALS, PLS, NLS, FA, and EIT (21 responses, yielding 48 terms: AED provider, ALS provider, Ambulance, Associate ambulance practitioner, Attendee, BLS provider, British Association for Immediate Care (BASICS), Bystander, Caretaker, Co-responder, Code blue team, Combat Medic, Community first responder (CFR), Do-gooder, Doctor / Physician, Emergency care assistant, Emergency care practitioner, Emergency Care Response Unit (ECRU), Emergency medical service (EMS), Emergency medical team, Emergency medical technician (EMT), Emergency medicine specialist, Firefighter / fire fighter / fire officer, First aid responder, First aider, First responder (FR), Hazardous area response team (HART), Helicopter EMS (HEMS), Helper, Lay rescuer, Layperson, Layperson rescuer, Life saver, Medic, Medical responder, Nurse, Paramedic, Police / Policeman, Professional first responder, Provider, Rescue squad, Rescue Squad Member, Rescuer, Responder, Resuscitation team, Resuscitationist, Samaritan, Witness).
A custom-built ChatGPT 4.0 model (programmed by AO) generated a draft search strategy, which was refined by an information specialist at the Medical University of Vienna. The strategy combined terminology-related keywords with descriptors of individuals attending cardiac arrest (e.g. “bystander”, “first responder”, “layperson”). The full strategy is provided in Supplement 1.
Inclusion and Exclusion criteria
Inclusion: Peer-reviewed articles in English (as translation of terms from other languages into English would not reflect their cultural-linguistic background) providing definitions or structured terminology for individuals or teams attending a cardiac arrest (any age, setting, role, or affiliation).
Exclusion: Articles without definitions or explanations of used terms, describing individuals or teams attending other emergencies, or merely using terms without further explanation. Grey literature was not included.
Data tables
Author (Year) |
Population / Setting / publication type |
Terms Used |
Description / Key Notes |
Definition / Nomenclature Provided |
Chamberlain et al. (1992) |
|
Bystander, Rescue squad member |
Called for structured reporting of responder tiers but offered no definition of roles. Used terms like bystander and rescue squad member without clarification. However, highlighted the importance of describing who provides which interventions, suggesting an early recognition of role categorization. |
Partial |
Zaritsky et al. (1995) |
|
Bystander, Lay responder, Citizen responder |
Provides detailed responder categorization. Defines bystander as someone not part of an organized response, even if medically trained. Synonymizes lay responder and citizen responder. Differentiates out-of-hospital vs. in-hospital contexts. Also provides pediatric-specific role classification, including witness types (e.g., family member, babysitter). |
Yes |
Jacobs et al. (2004) |
|
Bystander |
Defines bystander as a person not part of the formal EMS response. Extracted from the action-based term bystander CPR, the role is clearly assigned based on system affiliation, not professional background. Physicians, nurses, or paramedics may be considered bystanders if not officially dispatched. |
Yes |
Perkins et al. (2015) |
|
Bystander, EMS-witnessed |
Clearly distinguishes bystander from EMS roles, emphasizing that responder classification depends on system integration rather than profession. Supports role-based definitions in Utstein-style reporting. |
Yes |
Tirkkonen et al. (2017) |
|
Rapid response team |
A rapid response team was defined as any external response unit (physician led or not) providing assessment for a deteriorating patient in a hospital. However, this included all deteriorating patients, not only those in cardiac arrest. |
Yes |
Maurer et al. (2019) |
|
Bystander, App-responder, Off-duty nurse, Passerby |
Surveyed EMS professionals on classification of various responder types in fictional CPR scenarios. Explored real-world interpretations of responder categories (bystander, passerby, off-duty nurse), revealing inconsistencies in how these terms are applied. While no formal definitions are provided, the study contributes meaningfully to understanding terminology use. |
Partial |
Nolan et al. (2019) |
|
Resuscitation team |
Resuscitation team excludes a local response by the emergency department, operating room, or ICU teams. |
Partial |
Graesner et al. (2024) |
|
First responder, Volunteer community responder, Dispatched responder, Bystander |
A first responder was defined as being part of an organisation that has no capacity to transport a patient (e.g., police, fire brigade). A volunteer community responder was defined as alerted to the scene but having a choice to accept or decline the call. The term dispatched responder includes the EMS and first responders (should not be included as bystanders). A bystander is a person who is on scene or alerted but not dispatched as part of an organised response system (including off-duty health care professionals or volunteers). |
Yes |
Metelmann et al. (2025) |
|
Community first responder, Volunteer responder, On-duty responder |
Provides structured nomenclature via Delphi consensus. Distinguishes responders by activation context (work/leisure), and defines preferred terms (e.g., on-duty first responder, community first responder). Rejects others (e.g., professional first responder) for lack of clarity. Represents a formal attempt at nomenclature standardization. |
Yes |
Table 1: Summary of included publications, setting, terms used, and definitions provided.
Task Force Insights
1. Why this topic was reviewed.
This topic was chosen by the EIT Task Force because terminology to describe individuals or teams attending cardiac arrest was found inconsistent in published articles on resuscitation. The vast majority of resuscitation articles for OHCA and IHCA used such terms but only a few articles defined the terms used. This hampers comparability of registries and studies, and poses challenges for implementation, education, and communication.
2. Narrative summary of evidence identified
After screening of 7,148 records and duplicate removal, 23 full texts were assessed. Nine studies were included, most of them are Utstein updates or consensus documents from high-income countries (Table 1). Six (Zaritsky 1995, Jacobs 2004, Perkins 2015, Tirkkonen 2017, Gräsner 2024, Metelmann 2025) provided structured definitions (e.g., bystander, first responder, volunteer community responder, rapid response team). However, definitions varied widely, especially regarding bystanders (including or excluding off-duty professionals) or are lacking (e.g. lay person, first aider). Three studies highlighted inconsistencies without offering formal definitions (Chamberlain 1992, Maurer 2019, Nolan 2019). Terminology for IHCA remained especially unclear.
3. Narrative Reporting of the task force discussions
The TF decided not to report the respective countries the publications stem from because they are predominantly by large multinational author groups or working groups and no single country can be allocated to them. Just as the first or corresponding author’s country of living, or the country where the articles were published does not reflect the linguistic or cultural background of the entire group of authors. Of note, the survey among the ILCOR Task Forces alone resulted in a multitude of different terms, often only with linguistic differences and sometimes with cultural / regional aspects (e.g., with different First Responder systems).
The Task Force identified substantial heterogeneity in terminology of individuals or teams responding to cardiac arrest across all settings. Utstein templates improved structure but still define roles primarily from a registry perspective, not for implementation or education view. Ambiguities (e.g., off-duty professionals, app-based responders) remain unresolved. This is of particular importance because the views of the roles of individuals or teams responding to cardiac arrest are different from a registry-, education-, or implementation perspective; views and terms differ in the focus, purpose, and nature of interaction with the individuals involved. In essence, the registry view is focused on data and outcomes (with the goal of collecting uniform data to measure and improve the quality and effectiveness of resuscitation efforts), the education view on knowledge and skill transfer, and the implementation view on action and change management (individuals or teams involved as agents of change, required to adopt and integrate new protocols, equipment, or quality improvement cycles into the standard workflow). Thus, as of now, there is no clear system of terminology that is universally accepted and incorporates all different perspectives that are needed to describe the individuals and teams involved in the different links of the chain of survival. For instance, addressing the latest Utstein update (Gräsner 2024) its definitions do not align with a recent Delphi process results on first responders (Metelmann 2025). Specifically, in many countries, “First Responder” is a term including EMS units with the ability to transport but being BLS-units only – contradicting the current Utstein definition.
No studies addressed terminology in low-resource settings.
The Task Force concluded that international consensus is urgently needed to provide generally accepted terminology for the persons attending IHCA and the OHCA, which facilitates comparison of studies and systems. Such a broadly supported consensus might be performed under the lead of ILCOR. However, it needs to include healthcare professionals, scientists and researchers, health policy makers and health administration, representants of standardizing terminology systems (e.g. MeSH, ICD-11), journal editors, patient representatives and lay persons, best from different resource settings and cultural areas.
Knowledge Gaps
- No studies were identified from low- and middle-income countries, limiting the generalizability of findings to global settings.
- Terminology for in-hospital cardiac arrest responders (e.g., rapid response teams, resuscitation teams) remains insufficiently defined.
- The distinction between untrained bystanders, trained laypersons, and off-duty healthcare professionals is inconsistently applied across publications.
- Utstein templates provide registry-focused definitions but lack operational clarity for use in implementation, education, or legal frameworks.
- Ambiguity persists regarding the classification of app-activated volunteers, police, fire, and other non-transporting responders.
- No studies directly compared how different terminology affects registry coding, educational curricula and program evaluation, or implementation outcomes.
Supplement 1: Search Strategy
First Responders Concept:
(("Emergency Responders"[MeSH] OR "First Responders"[MeSH] OR "Health Personnel"[MeSH] OR "Paramedics"[MeSH] OR "Emergency Medical Technicians"[MeSH]) OR (layperson OR "lay person" OR "lay-person" OR "lay rescuer" OR "lay-rescuer" OR "layperson rescuer" OR "lay person rescuer"
OR bystander OR attendee OR "do-gooder" OR witness OR provider OR helper OR samaritan OR rescuer OR "first aider" OR "first aid responder" OR "life saver" OR "medical responder" OR responder OR "co-responder" OR "first responder" OR FR OR "community first responder" OR CFR OR "professional first responder" OR "BLS-provider" OR "BLS provider" OR "ALS-provider" OR "ALS provider" OR "AED-provider" OR "AED provider" OR "emergency medical service" OR EMS OR paramedic OR ambulance OR "emergency medical technician" OR EMT OR "rescue squad" OR medic OR "emergency care assistant" OR "associate ambulance practitioner" OR "emergency care practitioner" OR police OR policeman OR firefighter OR "fire fighter" OR "fire officer" OR nurse OR doctor OR physician OR "emergency medicine specialist" OR resuscitationist OR "emergency medical team" OR "resuscitation team" OR "code blue team" OR BASICS OR "British Association for Immediate Care" OR HART OR "hazardous area response team" OR HEMS OR ECRU OR "emergency care response unit" OR "rescue squad member" OR "combat medics"))
Nomenclature/Definition Concept:
(("Terminology as Topic"[MeSH] OR "Definitions"[MeSH] OR "Nomenclature"[MeSH] OR "Classification"[MeSH] OR "Taxonomy"[MeSH] OR "Semantics"[MeSH] OR "Descriptors"[MeSH])
OR (defin* OR describ* OR discussion* OR terminology* OR nomenclature* OR taxonom* OR term* OR phrase* OR label* OR naming* OR classification* OR semantic* OR descriptor* OR role* OR concept* OR identify OR meaning OR framework OR characterization OR interpretation OR "role definition" OR "role description" OR "conceptual framework" OR "conceptual model" OR glossary OR lexicon OR vocabulary))
Cardiac Arrest Concept:
(("Resuscitation"[MeSH] OR "Cardiopulmonary Resuscitation"[MeSH] OR "Heart Arrest"[MeSH] OR "Cardiopulmonary Arrest"[MeSH] OR "Ventricular Fibrillation"[MeSH] OR "Asystole"[MeSH] OR "Emergency Medical Services"[MeSH]) OR (resuscitat* OR ((cardiac OR heart) adj2 (massag* OR compression*)) OR (chest adj2 compression*) OR CPR OR "basic life support" OR "basic cardiac life support" OR BCLS OR BLS OR "advanced life support" OR ALS OR "advanced cardiac life support" OR ACLS OR "automated external defibrillator*" OR "automatic external defibrillator*" OR AED OR AEDs OR "cardiac arrest" OR "heart arrest" OR "sudden cardiac arrest" OR SCA OR "ventricular fibrillation" OR VF OR asystole OR "cardiopulmonary arrest" OR "cardiovascular arrest" OR "emergency response" OR "prehospital care" OR "emergency medical care" OR "code blue" OR "life-saving care" OR "emergency defibrillation" OR "chest compression-only CPR" OR "hands-only CPR" OR "shockable rhythm" OR defibrillat* OR "out-of-hospital cardiac arrest" OR OHCA OR "community resuscitation" OR "early defibrillation" OR "chain of survival"))
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