Table 1.

Data extraction of included studies

Study	Purpose	Design	Context		Respondent		Result
			Country	Type of ICU	Characteristics	Total
Santos et al. (2017) [17]	To explore perceptions of health professional related with end-of-life care and discuss they goals when planning a palliative care	Qualitative approach	Brazil	Oncology ICUs	Nurses (n=12), physicians (n=8), nutritionists (n=2), and physiotherapists (n=3)	25 Professionals participated	Barriers doing palliative care in oncology intensive care unit consist of prognostic disease of patient, lack of knowledge and interest in palliative care and reluctance to accept that it is no longer possible to keep seeking for a cure
Espinosa et al. (2010) [18]	To understand the experience of ICU nurses in providing end of life care is important first step to improving terminal care in the ICU	Phenomenological research study	United States	Adult ICUs	Participants consisted of women (n=15) and men (n=3) of nurses and with experience providing terminal care	18 Nurses	Lack of involvement, education, experience of nurses in the plan of care, disagreement and differences practice models among physicians and other healthcare team members, perception of futile care and unnecessary suffering, family unrealistic expectation
Ganz and Sapir (2019) [27]	To describe perceptions of Israeli ICU nurses about end-of-life nursing care (include palliative care), the intensity and frequency of barriers to providing quality end-of-life care and the correlation between them	Quantitative approach with personal and work characteristics questionnaire, the quality of palliative care in the ICU And a revised ICU version of the survey of oncology nurses’ perceptions of end-of-life care (sonpelc)	Israel	General/medical, respiratory/surgical, cardiovascular and neurological ICUs	Nurses from 2 hospitals	124 ICU nurses	Barriers providing end of life care in ICU such as communication between family, physicians and patients, and cultural differences leading to a lack of end-of-life discussions, and lack of palliative care education
Graw et al. (2012) [29]	To know advance directives influenced decision making of EOL on the ICU	Retrospective study	Germany	Surgical ICUs	Patients with terminal illness	224 Patients	Lack of communication and inadequate of documentation being challenges in providing end of life care
Kyeremanteng et al. (2020) [19]	To explore barriers towards palliative care-ICU integration	Online survey through email	Canada	Cardiac ICUs	Physicians (n=16), nurses (n=154), ICU fellow (n=5), palliative care staff physician (n=6)	181 Health workers	unrealistic patient or family expectations, disagreement about goals of care, different opinion of physician, and lack of communication skills as barriers to providing palliative care in ICU
Festic et al. (2012) [20]	To explore the differences of physicians and nurses on EOLC in the ICU and how these differences vary according to self-reported proficiency level and primary work unit	A cross-sectional study	United States	Adult ICUs	Physicians (n=50) and nurses (n=331)	381 Health professionals	Significant differences between physicians and nurses were noted in the following areas: ability to safely raise concerns, DNR decision making, discussion of health care directives, timely hospice referral, spiritual assessment documentation, utilization of social services, and the availability of EOLC education. In every domain of EOLC, physicians reported a more positive perception than nurses. Additional differences were noted among physicians based on experience, as well as among nurses based on their primary work unit and self-reported proficiency level.
McKeown et al. (2011) [21]	To explore in depth the Stirling Royal Infirmary ICU team’s views and experiences of the difficulties of providing palliative care in an intensive care setting, and identification of the dying patient	Qualitative interview-based study	Scotland, United Kingdom	Adult ICUs	Participants consisted of consultants (n=5), nursing staffs (n=10) and junior medical staffs (n=10), none of who were known to the interviewing researcher in advance	A total of 25 interviews were undertaken	The ICU team reported there to be a number of advantages to providing EOLC in the ICU in terms of access to nursing and medical care. They also reported there to be issues surrounding training, identification of palliative care patients and over-aggressive management. Further collaboration between ICU and palliative medicine is required to develop understanding between the two specialties and expand provision of palliative care in this unique clinical setting.
Friedenberg et al. (2012) [22]	To identify training- and discipline-based barriers among ICU nurses and physicians in attending training	Survey	United States	Medical ICUs	Residents (n=125), fellows (n=20), attendings (n=13), and nurses (n=60)	218 Participants	There were significant differences in reported barriers to EOL care by level of training, discipline, and institution, particularly in the education-training domain. Nurses’ perceptions of barriers to EOL care varied between institutions. Barriers that varied significantly between nurses included difficulty communicating due to language, inadequate training in recognition of pain and anxiety
Atwood et al. (2014) [28]	To compare oncology and CCPs' attitudes regarding palliative care	Electronic survey assessed using simulated patient description to identify respondents’ opinions of whether, when, and why palliative care should be utilized	United States	General ICU in academic hospitals	CCP (n=80), age ranged: 31–>60, years of experience 0–20 years, oncologist (n=72)	152 Professionals participated	The trained CCP were more likely to integrate PC based on patients' risk and morbidity.
							Women were more likely to incorporate PC in earlier the illness trajectory.
Attia et al. (2013) [23]	To investigate critical care nurses’ perceptions of barriers and supportive behaviors in providing EOL care to dying patients and their families.	Descriptive design	Egypt	Oncology, cardiology, hepatic and surgical ICUs	Nurses who involved in caring for critically ill patients	70 ICU nurses	Several barriers were perceived: environment; family members, nurses’ knowledge and skills, physicians’ attitudes and treatment policy.
					Oncology ICU (n=20)
					Cardiology ICU (n=15)
					Hepatic ICU (n=15)
					Surgical ICU (n=20)
Bluck et al. (2019) [24]	To identify perspectives of HCP at EOL in ICU and barriers to provide palliative care	Mixed method approach: open ended survey	United States	ICU	Resident and fellows (n=18),	39 Participants	Barriers providing palliative care in ICU included lack of care coordination, limited time, excessive paperwork, having a narrow knowledge base.
					nurses (n=10),
					attending physicians (n=6),
					advanced practitioners (n=2), quality improvement specialist (n=2), case manager (n=1)
Ozga et al. (2020) [25]	To understand barriers to EOLC in ICUs, and to identify difficulties perceived by ICU nurses providing EOL care in Poland	Qualitative approach	Poland	Adult ICUs	The participants of the study included register nurses from various ICUs from across Poland with at least 2-year experience working at an ICU	31 Individuals participated	The main issues raised during the interviews included (1) barriers attributable to the hospital, (2) barriers related to the patient’s family, and (3) barriers related to the ICU personnel providing direct EOLC. The interviewed nurses considered the lack of support from managers to be the main barrier. We found that ICU nurses in Poland dealt with end-of-life aspects that were emotionally and psychologically taxing. In addition, they lacked specialized training in this area, especially with regard to family care and care provision.
Silveira et al. (2016) [26]	To know the feelings of nurses regarding palliative care in adult intensive care units	Qualitative approach	Brazil	ICU	Participants of this study consisted of female (n=26) and male (n=4) nurses exercising their labor activities in the period of data collection and have at least one year experience in assisting adult palliative care patients in ICU, which may be current or past experience	30 Nurses participated in this study	The results showed how central ideas are related to feelings of comfort, frustration, insecurity and anguish, in addition to the feeling that the professional training and performance are focused on the cure.
Sharour et al. (2019) [30]	To explore the obstacles and strategies for improvement from nurses' perception of EOLC	Quantitative study with a multisite cross-sectional descriptive design	Jordan	ICU	critical care nurse from different governmental and private hospitals	163 Critical care nurses	The highest obstacles from the nurses’ perception were family and friends who continually call the nurse wanting an update on the patient’s condition rather than calling the designated family member for information. Furthermore, the highest three supportive behaviors from the nurses’ perception were physicians agreeing about direction of patient care, family members accept that patient is dying, family designating one family member as contact person for the rest of the family.

ICU: intensive care unit; EOL: end-of-life; EOLC: end-of-life care; DNR: do not resuscitate; CCP: critical care provider; PC: palliative care; HCP: health care professional.