Table 3 Additional study characteristics

Anderson et al

Interviews

Intensive Care Paramedics are the definitive PRPs attending most community cardiac arrests, although basic life support responders – often the New Zealand Fire Service – are commonly first at the scene. Medical advisors can be consulted by phone, but doctors rarely attend emergency callouts

N/A

Ethical approval by University of Auckland Human Ethics Committee (Reference No 016147)

Anderson et al

Semi-structured interviews

Emergency response is provided by paid and volunteer ambulance personnel of varying practice levels (First Responder, EMT, Paramedic, Intensive Care Paramedic)

EMT level and above are authorized to commence, continue, withhold or terminate resuscitation and verify the death per national ambulance clinical guidelines

Ethical approval by University of Auckland Human Ethics Committee (Reference No 016147)

Brandling et al

Focus groups with case vignettes

N/A

There is well-established UK clinical practice guidance, based on the 2015 UK Resuscitation Council Guidelines that indicates when EMS providers (paramedics) should commence and cease resuscitation in OHCA. These guidelines are used by EMS providers (paramedics) to make decisions on whether to commence ALS and whether to carry on or cease ALS in OHCA

No ethical approval. Participants signed consent forms before participants

Bremer et al

face-to-face interviews

The ambulance teams include at least one registered nurse, often a specialist in emergency, intensive, or anaesthesia care

NA

No ethical approval. Conforms to ethical principles in medical research involving human subjects as outlined in the Declaration of Helsinki. Written consent was obtained from study participants

Davey et al

An exploratory, interpretive study using Vx, a web-based ethical decision-making tool

New Zealand paramedics operate under three scopes of practice: EMT, intermediate life support, and intensive care paramedic. There are two land-based ambulance services and 21 air ambulances

N/A

Ethical approval by AUTEC, AUT University’s Ethics Committee

Karlsson et al

Interviews

Ambulance personnel in Sweden may hold one of three professional competence certifications: basic EMT with a vocational education or equivalent registered nurse with a 3-year bachelor degree, or specialist ambulance nurse with a 3-year bachelor degree and an additional 1-year specialist education at a university with a focus on pre-hospital care

N/A

No ethical approval. Followed the ethical principles according to the Swedish Research Council. Written and oral approval was obtained from the management officers of the ambulance service organisation. Participants were provided both oral and written information concerning the purpose of the study

Larsson et al

Semi-structured interviews

N/A

Physicians are authorized to commence, continue, withhold or terminate resuscitation

Ethical approval by The University Ethics Committee at Luleå University of Technology. Written and oral consent was obtained from participants

Leemeyer et al

Semi-structured interviews, focus group

Prehospital EMS in The Netherlands is primarily provided by ground ambulance crews staffed with a driver and a certified nurse. There are no ambulance paramedics in the Netherlands. A HEMS team consists of a helicopter pilot, a board-certified physician (either trauma-surgeon or anesthesiologist), and a specialized ambulance or emergency room nurse

While HEMS physicians have the ultimate decisive authority from the moment HEMS are dispatched, many of the decisions around traumatic cardiac arrest (e.g., initiating resuscitation or not, thoracic decompression, etc.) will have to be made by ground EMS in the absence of a HEMS team

The study was exempted by the local Medical Research Ethics Committee. No information on consent from participants

Lord et al

Focus group interviews

N/A

N/A

Ethical approval by Monash University Human Research Ethics Committee and the Queensland University of Technology (QUT) Human Research Ethics Committee. No information on consent from participants

Naess et al

In-depth interviews

The EMS system in Oslo is a one-tiered centralized community-run system for a population of 470 000. Each response team consisted of two paramedics, one team also included an anesthesiologist

The personnel follow standing orders and do not need to contact a base station to obtain permission before initiating or discontinuing therapy

Ethical approval by the Regional Committee for Medical Research Ethics. Informed consent was verbal, as a signed consent was thought to put unnecessary pressure on the participants

Nordby et al

Naturalistic, semi-structured interviews and a cognitive-emotional, interpretive approach

N/A

Paramedics are authorized to make resuscitation decisions. Contact with medical specialists and other health personnel is limited, and the communication typically happens through a narrow interactive communication channel

All participants read and signed a form that explained the nature of the research. They also signed a statement that explained the aims and scope of the interviews, and that their participation was voluntary and based on informed consent

Nurok et al

Fieldwork (Observations and informal interviews)

In Paris, pre-hospital emergency work is performed by physician-led mobile intensive care unit teams containing a minimum of a consultant physician and ambulance driver. In addition, teams usually included a senior medical student, resident, and nurse anesthetist

Given that emergency providers in the United States are supposed to provide minimal on-scene treatment, pre-hospital emergency providers are not as highly educated as they are in France. Calls result in teams of either Paramedics or First Aid providers being sent depending on the estimated severity of a case. These teams are often assisted by the Fire Department. Teams are supposed to follow strict protocols which stipulate action to be undertaken for any case. In New York, paramedics were able to call a physician for advice or authorization for certain treatments

N/A

No information on ethical approval or ethical aspects

Quantitative studies

Druwé et al

Survey

Doctors, nurses, and EMTs/paramedics working in emergency departments and the prehospital setting

N/A

Conducted in accordance with the Declaration of Helsinki. Unless informed consent was not required, the study was approved by the Institutional Review Board of all participating countries

Druwé et al

Survey

N/A

N/A

Conducted in accordance with the Declaration of Helsinki. Unless informed consent was not required, the study was approved by the Institutional Review Board of all participating countries

Haidar et al

Survey

This is a setting with an underdeveloped EMS system that lacks national standards for prehospital care

EMS volunteers in Lebanon get their training regardless of how far they reached in school and are not required to have any background in health education

N/A

No information on ethical approval or ethical aspects

Hick et al

Survey

The metropolitan area has a two-tiered dual response. Two-paramedic ALS ambulances respond to all ALS calls. In addition to the paramedic ALS unit, an AED (automated external defibrillator)-equipped first-responder unit is dispatched by the 911operator

Once radio contact is established, further therapy and disposition of the patient are determined by the paramedics in consultation with the physician; such decisions may include field termination of resuscitation, if appropriate

No information on ethical approval or ethical aspects

Johnson et al

Survey

N/A

In New Mexico, EMTs are taught to initiate CPR according to American Heart Association standards. EMTs are to initiate resuscitation on all patients unless decapitation, decomposition, or liver/rigor mortis exist

This study was reviewed by the University of New Mexico School of Medicine Human Research Review Committee

Leibold et al

Survey

N/A

Paramedics are prohibited from withholding resuscitation by German jurisdiction and therefore are obligated to initiate full resuscitation of patients with no vital signs, although they can of course express their opinions toward the physician's decision-making if a physician is present

Only the presence of severe injuries, which are not compatible with life and/or definite signs of death (e.g., livor mortis), legally absolve paramedics from withholding resuscitation

No ethical approval. Followed the Declaration of Helsinki

Meyer et al

Survey

Emergency physicians work on doctor-equipped ambulances

N/A

No information on ethical approval or ethical aspects

Mohr et al

Survey

N/A

Physician-staffed emergency medicine enables the emergency physician to decide on the termination of resuscitative efforts and to pronounce someone dead in the field

No ethical approval. The questionnaire was confidential and anonymous. The participants were informed about the objective of the study

Navalpotro-Pascual et al

Survey

N/A

N/A

No information on ethical approval or ethical aspects

Sam et al

Survey

N/A

N/A

Approval was obtained from the North Shore—LIJ Health System institutional review board. Participants were anonymised

Sherbino et al

Survey

This system is under the control of a medical director, who provides offline quality assurance without online medical delegation

Offline medical control is remote from the point of care (e.g., chart review or delegation by protocol). Online medical control refers to medical delegation over the phone at the time of patient contact

EMT-Ds are not required to initiate the resuscitation of a person with absent vital signs in the setting of decapitation, rigor mortis, or body decomposition

Stone et al

Survey

EMS is provided by the Los Angeles Fire Department, which has 3586 firefighters, of whom 767 are paramedics and 2819 are EMT-D

Denver has 128 EMT paramedics and 850 firefighter EMT-basics in a two-tiered system in which firefighter EMTs are the first responders and dual, hospital-based, paramedic ambulances are dispersed as the second tier. The firefighter EMT-basics are certified to use defibrillators

In almost all of the EMS systems in the United States, the initiation of resuscitation is mandatory in the absence of (1) a physician on scene superseding paramedic protocols; (2) clinical signs of irreversible death; or (3) a state-approved written DNR directive

No information on ethical approval or ethical aspects

Tataris et al

Survey

The Chicago EMS System is a regional collaborative of hospital-based EMS physicians and nurses that provide medical oversight for EMS provider agencies in the City of Chicago. The largest provider agency in the Chicago EMS System is the Chicago fire department, which provides exclusive emergency response for 9–1-1 calls in the City of Chicago

Emergency calls for OHCA identified at the point of emergency medical dispatch result in the tiered response of a 4-person basic or ALS fire suppression company; a 2-person ALS transport ambulance, and a paramedic field chief

The Chicago EMS System has had an out-of-hospital TOR protocol since 1995, although very few victims of OHCA underwent termination in the out-of-hospital setting despite meeting TOR criteria

No information on ethical approval or ethical aspects

Mixed-method studies

de Graaf et al

Registry data, semi-structured interviews

N/A

In the Netherlands, paramedics are legally allowed to make TOR decisions in the pre-hospital setting without consulting a physician. It is rarely documented which factors contribute to the decision to transport or terminate resuscitation of a patient when resuscitation appears to be unsuccessful

Ethical approval by The Medical Ethics Review Board of the Amsterdam UMC, Academic Medical Center. Written consent was obtained from participants

Waldrop et al

The survey, in-depth interviews

N/A

In the absence of a DNR order, prehospital providers have often been compelled to begin and continue resuscitation unless or until it is certain that the situation was futile and they have faced conflict when caregivers objected

Most EMS companies have had protocols in place that allow their prehospital providers to conduct TOR

The study protocols were approved by the University at Buffalo Social and Behavioral Institutional Review Board. All participations were voluntary and anonymous