Table 1 Characteristics and quality assessment of included studies

Qualitative studies

Pattison et al. (2013) [15]

UK

To explore the meaning of end-of-life care for critically ill cancer patients, their families, oncologists, palliative care specialists, critical care consultants and nurses

Qualitative, phenomenological, in-depth interviews

13 physicians

Gutierrez (2012) [16]

USA

To explore the experiences of critical care nurses and physicians with advance directives in an intensive care unit (ICU) to identify the benefits and limitations of advance directives and recommendations for improvement

Descriptive ethnographic study with interviews in a 22-bed medical/surgical ICU in a large community hospital

7 attending physicians, 3 fellow physicians

Barnato et al. (2012) [17]

USA

To explore norms of decision-making regarding life-sustaining treatments at 2 academic medical centres that contribute to opposite extremes of end-of-life ICU use

Mixed-methods study: family meetings, informal and formal interviews, and artefacts

Attending physicians at 2 academic medical centres, patients and family

Schenker et al. (2012) [18]

USA

To describe whether and how comfort care was presented as an option in family conferences about treatment options, and to assess whether the strength of the physicians’ belief that life support should be withdrawn was associated with the presentation of comfort care

Mixed-methods study of 72 audio-recorded family conferences about end-of-life treatment decisions

Physicians and family

Jox et al. (2012) [19]

Germany

To explore how clinicians themselves define medical futility, whom they think should assess this, how they justify performing futile treatment and how they communicate futility situations to patients and caregivers

Qualitative mixed-methods approach at a large tertiary referral centre used to analyse protocols of ethics consultations and semistructured interviews

7 physicians

Baggs et al. (2012) [20]

USA

To examine the role of the `attending physician’ in four adult ICUs and the consequences of role complexities for clinicians, as well as for patients and their families, particularly in the context of end-of-life decision-making

Ethnographic study in a large academic hospital with surgical, medical, cardiovascular and burn/trauma ICU, including observations of end-of-life discussions and interviews

30 physicians

Coombs et al. (2012) [21]

UK

To identify the challenges for health care professionals when moving from a recovery trajectory to an end-of-life trajectory in intensive care

Semistructured interviews in 2 ICUs in a large university-affiliated hospital in England

13 doctors

Ahern et al. (2012) [22]

Canada

Interview-based qualitative study conducted to identify what is important to physician trainees in the ICU and infer from this positive educational experiences for physician trainees

Qualitative approach of hermeneutic phenomenology, semistructured interviews

19 critical care physician trainees in their postgraduate years (R4 to R6)

Gehlbach et al. (2011) [23]

USA

Assess the concordance between patients’ code status preferences and their actual code status orders; compare patients/surrogates and their physicians regarding their respective assessments of most important goals of care

Survey, interviews with closed-ended and open-ended questions in a medical ICU of a large academic medical centre

15 physician participants

Schwarze et al. (2010) [24]

USA

To examine the culture and practice of surgeons to assess attitudes and concerns regarding advance directives for their patients who undergo high-risk surgical procedures

Qualitative study in trauma and surgical critical care

10 physicians

Corke et al. (2009) [25]

Australia

To examine attitudes of intensive care doctors to advanced care planning and medical enduring power of attorney

Survey followed by open-ended questions

275 trainees and fellows

Sibbald et al. (2007) [26]

Canada

To explore how frontline ICU staff defines medically futile care, to discover why they provide it and to identify strategies that might promote a more effective use of ICU resources

Qualitative interviews in 16 ICUs of academic and community hospitals

16 medical directors

Beck et al. (2008) [27]

Germany

To identify difficulties and uncertainties in making decisions about withholding and withdrawing mechanical ventilation among intensive care physicians

Problem-centred interviews

28 interviewees, 4 consultants, 11 senior registrars, 13 senior house officers (20 of 28 were specialists)

Baggs et al. (2007) [28]

USA

To clarify unit cultures surrounding end-of-life decision-making in 4 US adult medical and surgical ICUs

Prospective ethnographic study of 4 adult ICUs in which a 6-member research team used participant observations, field notes, and semistructured interviews of health care providers as well as patients and their families

13 physicians

White et al. (2007) [29]

USA

To determine the nature and extent of shared decision-making about end-of-life treatment in ICUs, which factors are predictive of higher levels of shared decision-making

Mixed-methods study: ICU family conferences in 1 county hospital, 1 university hospital and 2 community hospitals, as well as questionnaires to physicians

35 physicians leading conferences

Hsieh et al. (2006) [30]

USA

To identify inherent tensions that arose during family conferences in the ICU and the communication strategies clinicians used in response

Qualitative content analysis; communication between family members and physicians was analysed using a dialectic perspective in 51 family–clinician conferences in 4 hospitals

36 physicians who led the conferences

Palda et al. (2005) [31]

Canada

To explore the process of the provision of futile care in Canadian ICUs

Survey with closed- and open-ended questions

114 physicians

West et al. (2005) [32]

USA

To identify categories of expressions of nonabandonment in the setting of ICU family conferences concerning withdrawing life-sustaining therapy or the delivery of bad news, and to develop a conceptual model in which nonabandonment is expressed

Qualitative analysis of statements of abandonment during family conferences discussing withholding/withdrawing of treatment

35 physicians leading the conferences

Quantitative studies

Bülow et al. (2012) [33]

European countries (6 countries)

To examine whether religion and religiosity are important to end-of-life decisions and patient autonomy in the ICU

Structured questionnaires in 6 European countries, 143 ICUs

304 physicians

Schimmer et al. (2012) [34]

Germany

To determine the decision-making process of withholding and/or withdrawing of life-sustaining treatment in cardiac ICUs in Germany

Questionnaire distributed to all heart surgery ICUs (N = 79) in Germany

35 clinical directors, 25 senior ICU physicians

Kübler et al. (2011) [35]

Poland

To analyse the attitudes of ICU physicians regarding decisions to forgo life-sustaining treatment for adult ICU patients

Survey

217 intensive care physicians working in ICUs in Poland

Weng et al. (2011) [36]

China

To document current attitudes and practices of ICU doctors in China dealing with issues that have strong ethical and moral dimensions; to make comparisons with these attitudes and practices reported by ICU doctors in Hong Kong and Europe

Anonymous, written, structured questionnaire survey

315 participants, representing 54 ICUs in 30 cities in 21 of the 31 regions of China

Kranidiotis et al. (2010) [37]

Greece

To study the frequency, type and rationale for limiting life support in Greek multidisciplinary ICUs, the clinical and demographic parameters associated with limiting life support, and the participation of relatives in the decision-making process

Prospective observational study, with an anonymous questionnaire in 8 multidisciplinary, general hospital-affiliated ICUs

304 patients and their physicians

Schaden et al. (2010) [38]

Austria

To explore Austrian intensive care physicians’ experiences with, and their acceptance of, the new advance directives legislation 2 years after enactment

Survey of all ICUs in Austria

139 participants

Westphal and McKee (2009) [39]

USA

To examine differences between physicians and nurses regarding knowledge about advance directives and do-not-resuscitate orders, and the personal factors that underlie beliefs and practices related to the use of advance directives and do-not-resuscitate orders

Survey

53 physicians

Sprung et al. (2008) [40]

European countries (17 countries)

To evaluate physician documentation and the reasoning, considerations and difficulties in end-of-life decision-making in ICUs

Prospective study of end-of-life practices and decisions in consecutive patients who died or were subject to any limitation of life-saving interventions in 37 ICUs in 17 European countries

ICU physicians

Collins et al. (2006) [41]

Ireland

To study the frequency, rationale and process for withholding and withdrawing life-sustaining treatment in intensive care patients in Ireland

Prospective observational study of all consecutive patients admitted to ICU who died or had life-sustaining treatment limited

Data of 122 patients, documented by physicians

Nelson et al. (2006) [42]

USA

To improve the understanding of educational needs among residents caring for the critically ill

Survey

184 physicians

White et al. (2006) [43]

USA

To determine how decisions are made to limit life-sustaining treatment for critically ill patients who lack both decision-making capacity and surrogate decision makers

Prospective longitudinal cohort study

47 physicians of patients without decision-making capacity and without a surrogate

Moss et al. (2005) [44]

USA

To assess the knowledge, skills and attitudes that physicians and nurses who practice in West Virginia’s ICUs have concerning end-of-life care

Survey

153 physicians

Cohen et al. (2005) [45]

European Countries (17 countries)

To examine the communication of end-of-life decisions in Europe

Prospective observational study of 4,248 patients who had any limitation of life-sustaining treatment or died in 37 ICUs in 17 countries

Physicians collected data on 4248 patients

Élő et al. (2005) [46]

Hungary

To study the factors associated with limiting resuscitation in Hungary

Survey

72 doctors

Sinuff et al. (2004) [47]

Canada, USA, Sweden, Australia

To study the rate of establishing do-not-resuscitate directives, determinants and outcomes of those directives for mechanically ventilated patients

Multicentre observational study

3,099 critically ill patients admitted to 15 ICUs, documentation attending physicians' clinical judgements

Yap et al. (2004) [48]

Hong Kong

To examine ethical attitudes of intensive care physicians in Hong Kong

Survey

65 physicians

Hariharan et al. (2003) [49]

West Indies

To analyse the characteristics of moribund patients in a surgical ICU and highlight the dilemmas inherent in treating such patients

Prospective collection of data from patient records

Data of patients recorded by physicians of surgical ICU

Garland and Connors (2007) [50]

Canada

To quantify the influence that ICU staff physicians have on decisions to limit life support for critically ill patients

Data prospectively collected in the 13-bed medical ICU of a 520-bed urban university-affiliated teaching hospital

9 staff physicians