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Public Understandings of the Definition and Determination of Death: A Scoping Review

Background. Advances in medicine and technology that have made it possible to support, repair, or replace failing organs challenge commonly held notions of life and death. The objective of this review is to develop a comprehensive description of the current understandings of the public regarding the meaning/definition and determination of death. Methods. This scoping review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist. Online databases were used to identify articles published from 2003 to 2021. Two reviewers (S.S. and K.Z.) screened the articles using predefined inclusion and exclusion criteria, extracted data for specific content variables, and performed descriptive examination. Complementary searches of reference lists complemented the final study selection. A search strategy using vocabulary of the respective databases was created, and criteria for the inclusion and exclusion of the articles were established. Results. Seven thousand four hundred twenty-eight references were identified. Sixty were retained for analysis, with 4 additional references added from complementary searches. A data extraction instrument was developed to iteratively chart the results. A qualitative approach was conducted to thematically analyze the data. Themes included public understanding/attitudes toward death and determination of death (neurological determination and cardiocirculatory determination of death), death and organ donation, public trust and legal variability, and media impacts. Conclusions. This review provides a current and comprehensive overview of the literature related to the general public’s understanding and attitudes toward death and death determination and serves to highlight the gaps in this topic.


INTRODUCTION
In recent years, high-profile cases between families and healthcare providers have been prominently featured by the media and consequently have highlighted public interest in brain death and death diagnosis. [3][4][5][6][7][8][9][10][11] Prominent cases include several involving both children, like the McMath case in California in 2013, Lopez in Kentucky in 2014, 3,10,11 and Re A (a child) in the United Kingdom in 2015, 4 and adults, like the Munoz case in Texas in 2013 3,11 and the Hailu cause in Nevada in 2015. 9 Prominent Canadian cases include McKitty and Ouanounou, both in 2017. 12 These events are heavily published; although some have affected outcomes to resolve other brain death conflicts, others have caused increased suspicion and challenges of the diagnosis.
Spurred on by early work on the Uniform Determination of Death Act by the Uniform Law Commission, many scholars have called for an international consensus on the determination of death that could provide a number of benefits, including promoting evidence-based practices, protecting the rights of both patients and healthcare professionals, improving public and professional confidence in the process of deceased donation, and increasing the number of organs obtained for transplantation in an ethically legitimate manner. 1,2 An important first step in any attempt at developing a consensus on the definition of death is to better understand the general public's current views on the topic. The goal of this scoping review is to develop a comprehensive description of the current understanding(s) of the public regarding the meaning, definition, and determination of death.

MATERIALS AND METHODS
This scoping review was undertaken in accordance with the Joanna Briggs Institute methodology for scoping reviews 13 and in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews checklist. 14 As a scoping review rather than a systematic review, study inclusion was not limited by study quality or methodology, and all aspects of public understanding of death definition and determination were included.

Literature Search
We used a 2-step process for this review. The first step was to identify whether there exist similar systematic or scoping reviews on the topic of brain death meaning, definition, and determination. We searched online databases Ovid MEDLINE and Psych INFO to identify a known set of studies relevant to the topic. The topic was refined on the basis of identification of research gaps in the systematic review literature. Two independent reviewers (S.S. and L.H.) screened titles and abstracts in duplicate.
We then used key search terms identified from the systematic reviews during part 1 to refine the search strategy for a second search of online databases and gray literature sources. An information specialist searched electronic databases-Ovid MEDLINE, Ovid PsycINFO, and CINAHL-using controlled vocabulary (eg, Medical Subject Headings) and text words for concepts: death, organ donation, determination, and attitudes. R.F. also searched Conference Proceedings Citation Indices for meeting abstracts, ProQuest Dissertations and Theses Global for academic dissertations, and Google Scholar for any studies missed by the database searches. Search results were limited to studies published since 2003 in English. Duplicates were removed.
We included studies that explicitly discussed the public's attitudes toward concepts around brain death or circulatory death. We defined the "public" to include the citizens of any given country. Our search yielded many articles that described people's understanding of death/determination of death within the context of organ donation. In the context of organ donation and transplantation, the "public" and "families" became synonymous as many studies sought the opinion of families as their loved one progressed through the organ donation/transplantation processes. We excluded studies that only focused on either the organ donation/transplantation process itself or palliative care/end-of-life care without any discussion about the understanding of or attitudes toward death.

Screening
Two independent reviewers (S.S. and K.Z.) screened titles and abstracts using predefined inclusion and exclusion criteria. Articles were divided by stakeholder groups, healthcare providers, and the public. The focus of this scoping review is on the public perspective subset of the search. Both reviewers extracted data for specific content variables and performed the descriptive examination. The full text of selected citations was then retrieved and assessed in detail against the criteria by the 2 independent reviewers. Any disagreements were resolved through discussion.

Data Extraction and Synthesis
A data extraction instrument was developed to iteratively chart the results of the review. Extracted fields included authors, year of publication, country of origin (where the study was published or conducted if available, or country of the lead author), type of text, language, aims/purpose, study population, methodology, and key findings relating to the scoping review. All data were extracted from articles in duplicate (S.S. and K.Z.). S.S. and K.Z. also extracted data on the evolution of the death definition and public attitudes toward death and undertook qualitative content analysis of included studies. The codes were collapsed into themes that were used to write narrative summaries of each named theme. 13 Additional articles were identified from review of the reference lists of included articles and added for data extraction and complimentary searches of the literature. Figure 1 (PRISMA diagram) summarizes the search process and results, culminating in a total of 7428 citations. After removing 1451 duplicate citations, another 5763 were excluded on the basis of their title and on review of their abstracts. Full-text screening was undertaken on 214 articles. A further 23 articles were removed on the basis of full-text screening; reasons included focus on religion, end of life, healthcare provider, philosophy, and a duplicate article. A total of 60 met the inclusion criteria. Four additional articles were added from hand searches, resulting in 64 total articles included (see Supplemental Digital Content 1, SDC, http:// links.lww.com/TXD/A406 for list of articles) for data extraction (see again Figure 1 for the PRISMA diagram). Table 1 provides a listing of the characteristics of included articles. The most common study type was narratives (25), followed by reviews (11), and the most common method for collecting data from the public was through quantitative studies (17). Most studies originated from North America (33) and Europe (14). Emergent themes are presented in Table 2.

Public Understanding Toward Death and Death Determination: Neurological Determination of Death
Since its inception in 1968, the concept of whole-brain death has been contentious. 15 Although it is recognized and widely accepted as death in North America and elsewhere across the globe, there exists "medical, moral, and philosophical" disagreement mainly from healthcare professionals. 16 This review found that the public has a general awareness and acceptance of brain death; however, they have a poor understanding of the meaning of brain death and confusion with other brain conditions such as coma and persistent vegetative state. Brain death is defined as a loss of function of the brain, but declaring brain death does not require the death of every neuron. 17 This only serves to highlight the ongoing confusion over the current definition of brain death and fuels the need for an international change in the legal definition of death.
Twenty-two studies located reveal that the overall public understanding of brain death is indeed poor. 3,11, Twentyfour empirical studies were identified that examined the public's understanding of death and its determination using quantitative, qualitative, and mixed methodologies (Table 3). Siminoff et al 17 found that a sizable number of people (30%) in their study agreed with the statement "a person is dead only when the heart has stopped beating." Even among those who had good knowledge of the brain death diagnosis, it is often difficult to accept it as a true death. 33,36,45 The appearance of life in brain death, with warm skin, a heartbeat, and breathing even with the help of a machine, complicates the family's acceptance of the death of their loved ones and the diagnosis. 5,15 Brain death creates cognitive dissonance and conflicts with the schema of a dead body (cold, motionless, does not breathe). In these situations, temporary ventilator disconnection, a routine part of the examination to confirm the absence of the ability to breathe to establish the brain death diagnosis, may be an effective way of helping families understand and accept brain death. 2,45 Studies show that public comprehension of the distinctions between brain death, a coma (temporary gross impairment in brain function), and a persistent vegetative state (a permanent unconscious state with retention of the ability to breathe without assistance and preservation of some brainstem reflexes) is poor. 3,11,21,46,47 Other studies have reported similar findings in that people believe that brain death does not mean a person is dead and that it is not the same as "natural death." 17,24,27,29,30,43,48 Other studies showed that people believed that brain-dead patients were still alive or would recover. 25,43,48 In other countries like Japan, the cessation of brain function is not necessarily felt to be representative of the cessation of life while other organs such as the heart continue to function. 49 Public Understanding Toward Death and Death Determination: Circulatory Determination of Death Circulatory determination cases involve declaration of death very quickly after loss of circulation, whereas without donation, there is extended time to observe death after loss of circulation. Of the few studies located regarding the public's understanding of death by circulatory criteria, all were in the context of organ donation and transplantation. 39,40,50,51 Only 3 studies explicitly focused on asking participants about the determination and timing of death. 40,41 Neiders and Dranseika 41 found that circulatory criteria of death were the least preferred by participants compared with whole brain and higher brain death for their own death determination but preferred over higher brain death criteria for their relatives. Joffe et al 40 asked university students (undergraduate medical students, nursing students, and philosophy students) to consider if patients who donate organs after circulatory death are really dead. The majority of students in all 3 groups were not confident that a donation after circulatory death (DCD) donor was actually dead. Interestingly, it was the medical student group who were less likely to agree that the DCD patient was dead 45 and mainly cited the concept of irreversibility as adding to the confusion. This study concludes by stating that depending on how questions are asked, there is no uniform acceptance that the DCD patient is dead. 40 A third study by Verble et al 44 sought to determine the primary concerns of families who were approached for DCD. The authors found that family concerns regarding DCD differed in significant ways than in donation after brain death. Of the 16 main concerns, 44 not one focused on difficulties in understanding death. Overall, there have been minimal investigations regarding public perceptions in the domain of circulatory determination of death.

Death and Organ Donation
The literature on the public's understanding of death and death determination is closely linked to organ donation and transplantation. Given this context, it is important to understand how death, particularly brain death, may be perceived The public's understanding of brain death and its relation to organ donation Public trust in HCPs and the healthcare system The relationship between public confidence in care at the hospital level and healthcare system level Media, colloquialisms, and brain death How the media acts to inform (or disinform) the public about brain death DCD, donation after circulatory death; HCP, healthcare provider; NDD, neurological determination of death.   how those might be addressed to increase DCD donation rates. Family concerns that block DCD differs in many ways from those of BD families. Results from DCD family concerns were grouped into 3 overlapping categories: practicalities, suffering, and process. BD, brain death; BSD, brain stem death; DCD, donation after circulatory death; DCDD, donation after the circulatory determination of death; DNC, death determination by neurological criteria; HCP, healthcare provider; ICU, intensive care unit; NDD, neurological determination of death; OPO, organ procurement organization. The majority of studies located focus on brain death and organ donation and, in particular, the public's lack of knowledge surrounding brain death determination when making donation decisions. [31][32][33][34][35] Studies have demonstrated that some people feel that if they agree to organ donation for their loved one, those patients may be diagnosed as dead too soon. 17,52 One study showed that although 80.1% of family members would allow for organ donation after the death of a consenting relative, this rate dropped by 20% when the word death was substituted with brain death, revealing a lack of either understanding or acceptance of the concept and their legal equivalence. 20 Four recently published empirical studies found that the greater the knowledge of brain death and organ donation, the more families shared a positive impression or attitude toward donation. [31][32][33]35 A Latvian study found that study participants had widely different preferences concerning death determination criteria between higher brain, whole brain, or circulatory criteria. Interestingly, participants preferred less restrictive criteria for both their own death determination and organ transplantation than for their relatives (P < 0.001). 41 Similarly, Siminoff et al 17 illustrated how the general public have different conceptions of death than medical criteria, for example, brain death is a technical and medical term to signify a person is dead by neurological criteria. However, brain death is also used in common language as meaning that a patient is severely brain injured. 17 The fact that a sizable number (60% of the sample) of people were willing to donate organs of people who were not legally dead is of importance and suggests that more education is necessary to further educate the public to better understand the concept. 17

Implications for Public Trust and Legal Variabilities
Public trust in the healthcare system and its providers is an essential factor for public buy-in to brain death regulation and for the public to subsequently trust in the brain death diagnosis. 19,23,53,54 In instances where there is a lack of trust in the healthcare system, there is decreased support for and trust in the brain death diagnosis. This was especially found in Eastern countries like Japan and China, where there have been past or present physician-patient conflicts, 49,52-54 with surveys in Japan showing only a 40% support for defining brain death as legal death. 49 Racial minorities in Western countries have also shown to have less support for brain death, attributable to decreased trust in the healthcare system. 3,18,39 This distrust seems to have persisted despite legal and medical acceptance of brain death, thus suggesting that trust in healthcare providers and the medical system may be a more significant factor for public buy-in to brain death than the legal status of the diagnosis. 25 DuBois and Schmidt found that the general public is hesitant to have death be determined through legal criteria. In contrast, a significant proportion (66%) trusted the healthcare system, and several suggested that the criteria for determining death should be undertaken by physicians and the public instead of the law. 25 Legal variability in the determination of brain death may also give a sense of arbitration that perpetuates the confusion and mistrust in the diagnosis. This has fueled many highprofile court cases challenging it, which may contribute to increased erosion of public trust in the concept. 8 For example, in the United States, the legal standard for brain death determination is variable between states, with a few (ie, New Jersey, California, New York) recognizing moral or religious objections to the determination of brain death to varying degrees and occasional deferral to the circulatory criteria. 8 On the contrary, a Polish survey found that trust in the brain death diagnosis among nonmedical respondents was significantly lower than medical respondents (38.5% versus 78.5%), 19 which could not be solely explained by lack of knowledge. Doubts over the criteria itself (31.5%) and distrust of medical staff's education (25%) and objectivity (20%) also contributed. 19 Educational background was also shown to affect the level of trust. 19,40 Joffe et al 40 found that medical students were less likely than nursing or philosophy students to trust that physicians were truthful in describing DCD patients as dead.
Ultimately, when lack of trust among the general public exists, several key concerns have also been linked, including that brain death may be erroneously and prematurely diagnosed, that the patient will not be dead at the time of organ donation, that care may be withheld or prematurely terminated in favor of organ donation, 10,20,39,44,49,55 or that they themselves were uncertain about the concept of brain death. 19,20 One potential solution in situations where there is a lack of trust in healthcare providers could be to obtain independent confirmation of the diagnosis to have family present at the time of brain death assessment and diagnosis, 9 including during temporary ventilator disconnection that occurs as part of brain death determination. Such an approach may help families better understand and accept brain death. 46 Building the public's trust in the reliability of the diagnosis seems to be pivotal to increasing their acceptance of brain death. 19 Data from other countries have shown that public consultation may further intensify the rift and be ineffective for achieving a resolution. Despite significant public discourse and legal changes favoring brain death determination, brain death remains a highly controversial topic among the public, such as in Japan. 28 Similarly, in Denmark, after brain death was opened up for public examination, the result, surprisingly, was greater uncertainty and lower organ donation rates, despite the huge economic investment by the government to sponsor large public hearings, public debates, educational films, and programs on national television. 23,48 Media, Colloquialisms, and Brain Death The majority of references identified with respect to media representations of death typically focus on brain death. 5,10,19,[22][23][24]27,31,[55][56][57][58] Brain death is often used colloquially and represented in the media, shown on the news or in medical dramas on television (see Table 4). The depiction of brain death via the media is one of the most significant factors in spreading awareness of the brain death concept among the public. One study showed that 85% of students who had already heard of brain death had heard of it from the media (35.7% from television, 8.3% from radio, 41.2% from the internet), 24 whereas another showed that because of televised medical dramas, families sometimes felt a personal realization that their relative had died, even before the medical confirmation of brain death. 22 In a nationwide Turkish survey, adult participants identified that their main source of information about brain death was the television, and 85% of participants indicated that they refused to consent to donating organs of family members declared brain dead. 31 On the other hand, it is apparent that although the media plays an important role in shaping the views of death, it does not often provide an accurate representation of either its definitions or implications. When brain death is discussed in the news, the actual diagnostic criterion is rarely mentioned, and when it is, it is often misrepresented as purely the cessation of cardiorespiratory function. 38 The media has also played a significant role in perpetuating distrust over the irreversibility of brain death, with reports of patients in a persistently vegetative state spontaneously awakening being confused with the brain death state and undermining trust in the diagnosis. 19 Popular medical dramas like Grey's Anatomy have also been found to misrepresent and dramatize reality by exploiting and perpetuating people's fears of having organs recovered for transplantation while falsely declared brain dead. 55 Furthermore, the language around death and dying used in the media continues to perpetuate the confusion and misunderstandings among the general public 17,23 and to further degrade public confidence. 10 For example, terminology such as "sleeping," "being kept alive on the ventilator," and being on "life support" grossly misrepresents an individual who is brain dead, and the use of such terms undermines the message that death has already occurred. 5,23 Headlines in the media are often either sensationalized or oversimplified, which further colors the public's understanding and perception of brain death. 5,57 Media reports of rare cases of genuine misdiagnosis of brain death have received intense coverage that has harmed public perceptions. 10 Studies have found that receiving negative information on brain death from television was in fact associated with less acceptance of brain death as actual death of the patient than among those who did not receive such information from television. 27,31

DISCUSSION
The 64 references identified in this scoping review revealed important themes and highlighted gaps in the literature regarding the public's perceptions of death and death determination. Although the public generally concedes the concept of brain death (ie, they accept it), their overall understanding is poor. More specifically, public misunderstanding stems more from confusion about the medical and legal facts concerning death determination, particularly in brain death cases. 3,11,41,45 Death in the context of organ donation introduced more complexity. 10  Media representation and impact on public understanding of brain death (n = 12)

References
Type of article Country Comments

Al Bshabshe et al 24 Quantitative/Survey Saudi Arabia
Eighty-five percent of students who had heard about BD got information from the media sources (35.7% from television, 8.3% from radio, 41.2% from the internet, and 14.6% from friends). Akbulut et al 31 Quantitative/Survey Turkey Only 47.2% of participants said they had inadequate information about BD, and 85.2% refused to consent to donating organs of family members declared brain dead. The majority of participants said they got their information about BD from television. Crippen 5 Review United States Misleading media statements and terminology such as "sleeping," "on life support," and interpretation of movement as life as well as sensational media headlines color the concept of BD. Daoust and Racine 38 Qualitative/Focus Group Canada Analysis of 940 American and Canadian newspaper articles showed similarities in their coverage of BD. It showed that BD is used colloquially in 39% (n = 366) of articles and the medical meaning is infrequently defined (2.7% and 3.6% in the United States and Canada). NDD criteria are mentioned in <10%, and life support in 20%. There is a need to bridge media representations of NDD with experts' views. The media often misunderstands that BD is not death until cessation of cardiopulmonary functions. Febrero et al 27 Quantitative/Survey Spain Knowledge of BD was not associated with having received information through audiovisual means (radio, daily press, magazines, films, advertising hoardings) or talks in education centers. It was associated only with having received negative information through television, which led to a worse knowledge of BD compared with when no information was received through television (36% vs 41%). Haddow 22 Qualitative/Focus Group United Kingdom Semistructured interviews with 19 Scottish donor families revealed that many participants knew about brain stem death from televised medical dramas. This previous awareness from medical dramas helped relatives gain a personal realization of when death had occurred, sometimes even before the medical confirmation. Kilcullen 55 Review United States Media significantly influences public view of organ donation, often mischaracterizing BD and fostering confusion (medical shows like Grey's Anatomy, major newspapers). Knox 58 Review Australia Screen representations evidence the preoccupation, culturally with mechanisms by which individual identity may be preserved in death. Laureys 56 Narrative/Opinion Belgium Misleading term of BD as suggesting 2 different types of deaths may explain public and professional confusion about BD. Much of the controversy results from confusion/ignorance by the public or policy-makers about the medical reality of BD. Long 23 Qualitative/Focus Group United Kingdom Qualitative studies show that use of terminology like "kept alive on a ventilator" and "life support" to describe BD undermines the message that death was inevitable. Nowak et al 19 Quantitative/Survey Poland The media has reported instances of patients in a persistent vegetative state spontaneously awakening; however, this has been misrepresented as awakening from BD. Pope 10 Review United States Families regularly bring lawsuits to mandate continued physiological support, religious objections, or just mistrusts the diagnosis. Confusion in how media reports on BD has damaged public confidence. Reports of genuine BD misdiagnosis/premature diagnosis (intention or negligent) have received intense media coverage and subsequently caused public alarm. Thomas 57 Narrative/Opinion Australia Public debate about BD often leads to oversimplified media statements, with the potential to undermine public support for organ donation. BD, brain death; NDD, neurological determination of death.
brain death and organ donation reflect substantial public confusion" about medical and legal facts, 59 which is not surprising given the complexity of this issue. More specifically, in the context of a brain death diagnosis, a family member's acceptance of the diagnosis of death "of someone who is still breathing and whose heart is still beating seems to violate a basic understanding of what constitutes life." 45 Freeman 45 explains that it takes an "unnatural leap of faith to understand brain death cognitively based on the word of a complete stranger, rather than based on direct observation." The media acts to further confuse the general public with loose use of terminology and portrayals of death in medical dramas and newspapers, which are often sensationalized, oversimplified, or inaccurate in their representation of death. 22,24,31 It is important to ensure that there is adequate public education and awareness of brain death and also that the sources and quality of the information more closely match reality. Data suggest that the public generally concedes the concept of brain death, that is, they accept the diagnosis from physicians; it is important to note that this is not a uniform finding. Specific countries/contexts/populations may be less accepting of this definition of death. Limited global data resulting from our search criteria make drawing conclusions impossible.
More empirical inquiry needs to focus on understanding the public's attitudes and perceptions on death in the contexts of death determination by neurological and circulatory criteria, as well as ongoing public understanding of the distinctions between death determination and organ donation. More investigation into determining the optimal strategy for ongoing, meaningful public engagement on this topic is needed. Only 2 empirical studies in this review, 1 Canadian 40 and 1 American, 44 explored the views of participants regarding understanding of death and death determination from a circulatory determination perspective. 40,44 Interestingly, this review has served to highlight the fact that public engagement alone may not lead to a more cohesive and unified definition of death, suggesting that how the public is engaged may be just as important as if they are engaged. From experiences of other countries such as in Denmark and Japan, a lesson learned is that in itself, increasing the involvement of the general public in the debates and legislation around death determination may not necessarily increase public acceptance and may perpetuate heated discourse not necessarily based on a strong conceptual foundation. 10,23,48,53,60,61 In contrast, the public should not be overlooked in attempting to implement health-related policy. As Bruni et al 62 noted, "the public is the most important stakeholder in the healthcare system" and "members of the public can provide a crucial perspective about the values of a community which should lead to higher quality decisions in priority setting." And, preserving public trust in healthcare providers and the medical system in general should be one of a country's highest priorities.

Limitations
Although comprehensive in scope, the review was limited to English language publications. Also, we are limited in that our review search was conducted until July 31, 2021, and as a result, we may have missed articles published after that initial search. Finally, our search strategy included studies that focused on the public's understanding of death and death determination both outside of and within the context of organ donation and transplantation that may have an impact on the attitudes of people in these studies.

CONCLUSIONS
This scoping review provides a comprehensive overview of the published literature related to the general public's understanding and attitudes toward neurological and cardiocirculatory determination of death. We have affirmed that the literature on the public's understanding of death and death determination is closely linked to the organ donation and transplantation domain, and there need to be ongoing efforts to clarify the processes surrounding death determination and organ donation practices. We have identified a need for empirical research, in particular Canadian research, on the attitudes and views of the public on death determination with specific focus on death by circulatory determination. The issue around public trust in healthcare providers and the healthcare systems and the impact of popular media on the awareness and understanding of brain death have both significantly impacted how death determination is perceived by the general public. In particular, trust in healthcare providers and the medical system at large may be a more significant factor for public buy-in to death determination than the legal status of the diagnosis. There is much to be learned from experiences of other countries with public engagement around death determination. However, as part of any initiative for general understanding, the public should be consulted in death determination discussions, and thus, any agenda for death determination must engage with and include the public representation.