Systematic Review of Conceptual Frameworks used in Palliative Care Research Studies

Abstract

Background:

Theoretical conceptual frameworks are often used in palliative care / end-of-life care research studies, to help with study design, guide, and conduct investigations. While increasing number of investigators have referenced theoretical frameworks in their study, to date, there has not been a comprehensive review of conceptual frameworks guiding palliative care research.

Aim:

First, to identify can characterize conceptual or theoretical frameworks used in palliative care / end-of-life care research studies; and, second, to examine which domains from the Clinical Practice Guidelines (CPGs) for Quality Palliative Care (4^th edition) are addressed in each framework identified.

Design:

Systematic Review

Data sources:

Four electronic databases (EMBASE, the Cumulative Index to Nursing and Allied Health, PsychINFO, and PubMed) were utilized for literature search.

Results:

A total 2,231 citations were retrieved. Forty-four articles met eligibility. Across studies, 33,801 study participants were captured. Twenty-six investigators (59.1%) proposed previously unpublished frameworks. In 10 studies, investigators modified existing frameworks, mainly to overcome inherent limitations. In 8 studies, investigators utilized existing frameworks that were referenced in previously published studies. There were 8 orientations identified among 44 frameworks we reviewed (e.g., system, patient, patient-doctor). Twenty-one studies (47.7%) covered a single CPG domain, while the rest two or more of CPG’s eight guidelines in quality palliative care domains.

Conclusions:

We examined palliative care literature to identify and characterize conceptual frameworks used in palliative care/ end-of-life care research studies. Of 44 frameworks we reviewed, more than half were new frameworks, and many frameworks addressed one to two CPG domains.

Background

Palliative care, a specialized type of care designed to enhance quality of life for those who are living with serious illnesses, is patient as well as family-centered care and focuses on symptom relief (e.g., pain and associated symptoms).(1, 2) Palliative care is associated with relief of distressing symptoms,(3–5) higher levels of satisfaction with care for patients and families,(6–9) and significant healthcare savings costs.(10–12) Indeed, individuals who do not receive palliative care are noted to have poorer quality of life and shorter survival times.(3, 6, 13) It is estimated that approximately 40 million people around the world are currently living with serious illnesses,(14) making them candidates for palliative care.

Despite the dire need for provision of palliative care, only 14% of individuals who need palliative care currently receive it.(15) In addition, high quality palliative care services (e.g., interdisciplinary palliative care teams) have not yet been established across all care settings, jeopardizing the quality of care provided. To improve and standardize the quality of all palliative care using evidence-based processes and practices, the National Coalition for Hospice and Palliative Care has developed the Clinical Practice Guidelines (CPGs) for Quality Palliative Care, 4^th edition.(16) These guidelines identified 8 domains of practice essential to quality palliative care: 1) Structure and Process of Care, 2) Physical Aspects of Care, 3) Psychological and Psychiatric Aspects of Care, 4) Social Aspects of Care, 5) Spiritual, Religious, and Existential Aspects of Care, 6) Cultural Aspects of Care, 7) Care of the Patient Nearing the End of Life, and 8) Ethical and Legal Aspects of Care.(16) The CPGs aim not only to guide practice but also to shape research. Careful study design, aligned with the new CPGs, can generate strong research evidence that contributes to improving palliative care.

Given the increased attention towards palliative care, there has been commensurate development of conceptual frameworks guiding palliative care research. However, to date, there has not been a comprehensive review of existing palliative care conceptual frameworks, which identifies and characterizes them using a quality lens. Therefore, the purpose of this paper is to report on a systematic review of the literature in which there are two aims: 1) identify and characterize conceptual or theoretical frameworks used in palliative care research studies and 2) examine which domains from the CPGs for Quality Palliative Care are addressed in each framework. This comprehensive review of existing palliative care conceptual frameworks aimed at improving quality palliative care can be used across settings of care to standardize quality research and practice in palliative care.

Method

Protocol and registration

To conduct this systematic literature we used well-known best practices, which included the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.(17)

Information sources

The final literature search was performed July 1, 2020 using four electronic databases: EMBASE, the Cumulative Index to Nursing and Allied Health, PsycINFO, and PubMed. Searches terms included keywords and medical subject headings (MeSH) palliative care, serious illness, and theoretical framework. Prior to beginning the search, two authors (A.T., L.V.E.) reviewed the search strategy with a library informationist who is a systematic review specialist. In addition to this main search, a lateral search was conducted by manually searching reference lists from the included studies. The search strategy utilized for each database are outlined in Appendix 1.

Eligibility Criteria

All peer-reviewed, English-language studies focused on palliative care in adults that addressed or referenced a conceptual framework, conceptual model or theoretical framework (from here on referred to as framework) that met our inclusion criteria were included. Palliative care was defined using the National Quality Forum definition,(16) which is patient/family-centered care aimed at optimizing quality of life by anticipating, preventing, and alleviating sufferings across the continuum of a patient’s illness. Study inclusion criteria were: 1) all study designs (e.g., qualitative, quantitative, mixed methods, and interventional studies), 2) in any healthcare settings (e.g., hospice, hospital or homecare and 3) involving adults (age 19 years and older) meeting criteria operationalized as: seriously ill individuals in need of expert symptom management and care that aligns with their preferences and goals.(18) Studies were excluded if conceptual frameworks were not addressed/ referenced.

Study selection and Data Extraction

Search results were imported into EndNoteX9, which was then used to remove duplicate studies. A two-step study selection process was conducted. In the first step, two authors (A.T., L.V.E.) independently performed title and abstract screening of all included studies using a web-based literature screening tool, Covidence.(19) A standardized abstract screening tool (Appendix 1) was utilized to assess study eligibility. Any disagreements between two authors were flagged and such cases were resolved through discussion between two authors until consensus was achieved. The results from this step were then presented to the team for review and discussion.

In the second step, full-text review of studies, which were retained from the title/abstract screen was conducted. At this point, each study was re-assessed for its adherence to eligibility criteria. Any disagreements were resolved through bi-weekly discussions held with a third reviewer (H.B) until consensus was reached. Once again, the final corpus was presented to the team and finalized after careful discussion.

Using Microsoft Excel to manage the data, we extracted the following information: author, year, country of study origin, study aim, study design, setting, sample size, sample characteristics, and study findings. We then retrieved framework-relevant information (i.e., name of framework, description, and key components) to address our aim. We also identified whether the frameworks were new or existing, or an adapted/modified version of existing frameworks.

Data Analysis and Synthesis

For data analysis and synthesis, we implemented a multi-stage qualitative process.(20, 21) First, an analysis of the CPGs for Quality Palliative Care (4^th edition)(16) was conducted to derive benchmarks against which to adjudicate the frameworks. These included definitions and additional keywords for each domain in the CPGs (Table 1). Next, after a careful reading of the description of each framework, its specific orientation (i.e., towards doctor, patient, patient-caregiver, caregiver, patient-doctor, patient-system, patient-nurse), as well as main and sub-components of each framework were identified. This information was then compared to the benchmarks from the CPGs.(16) This was accomplished by having two authors (A.T. and L.V.E.) independently code the orientation, main and sub-components using Atlas.ti. The coding identified any representative keywords shared by the framework and the CPGs for each domain. When any disagreements arose between coders, additional team members were engaged to review the contents together and refined keywords until both were in agreements. When the coding was concluded it was then verified by the full team to assure that keywords aligned with CPGs’ definitions and were supported by exemplars. Frameworks were then assigned to one or more respective CPG domains (Table 1). Finally, all team members reviewed the synthesized data table to confirm findings. Because the purpose of the study was to identify any frameworks and which CPG domains were addressed, the overall quality of the study design was not assessed.

Table 1.

CPG definitions, keywords and examples by Domain

CPG definition of each domain (bolded terms indicate keywords)	Additional CPG keywords used to adjudicate frameworks	Exemplars (framework title/description)
Domain 1: Structure and Processes of Care
Palliative care be integrated into any health care setting and be delivered by interdisciplinary team with necessary qualifications and training of medical providers. It begins with comprehensive assessment, patient/family engagement, communication and care coordination	Comprehensive care; Holistic Care; Development of Advance Care Planning/discussion; decision making; Policies and Procedures; teamwork	The domains of physicians’ skills at providing high quality End of Life care (Curtis, J., 2001)
Domain 2: Physical Aspects of Care
Physical care of seriously ill patients begins with understanding of goals in physical, functional, emotional, spiritual well-being aspects. Assessment and plan of care should be focused on relief of physical symptoms, improve/maintaining functional status and quality of life. Care management encompasses the use of pharmacological, non-pharmacological, interventional, behavioral and complementary treatments	Anticipation of pain; pain medication management; symptom management education	Lung Cancer Symptom Scale-Meso Conceptual Model (Hollen, P., 2004) Symptom distress due to illness and/or functional dimension influence overall quality of life associated with mesothelioma experience
Domain 3: Psychological and Psychiatric Aspects of Care
Systematically assesses psychological and psychiatric aspect of care in serious illness. Conduct a comprehensive developmentally and culturally sensitive mental status screening of seriously ill patients. Social worker facilitates mental health assessment and treatment in all care settings. Provide necessary support for patient and family (grief support, referral for specialist)	Emotional/mental health; psychological well-being, stress	Good rural death (Veillette, A. M., 2010) Essential domains for a good death includes physical, Spiritual, Social, Emotional/Psychological domain
Domain 4: Social Aspects of Care
Palliative care addresses environmental and social factors that affect patient and family functioning and quality of life. Partner with the patient and family to identify support system, strength and area of need. Includes a social worker to maximize patient functional capacity and achieve patient/family goals	Assessment of family needs; financial impact of serious illness; family and patient support; support system relationship	Behavioral model of health services utilization (Kwak, J., 2008) Factors influencing health services utilization include social forces, family and economic resources, need for care
Domain 5: Spiritual, Religious, and Existential Aspects of Care
Spirituality as a fundamental aspect of compassionate, patient/family-centered palliative care. It is a dynamic and intrinsic aspect of humanity through which individuals seek purpose, transcendence, and experience relationship to self, family, others, community, society and the significant or sacred. Spirituality is expressed through beliefs, values, traditions, and practices	Integration of faith; respect towards other’s beliefs; spiritual care education	The Senses Framework: improving care for older people through a relationship-centered approach (Nolan, M., 2006) Quality care of elderly patient should include a set of senses: sense of security, continuity, belonging, purpose, fulfilment, and significance
Domain 6. Cultural Aspects of Care
Assessing and respecting values, beliefs and traditions related to health, illness, family caregiver roles and decision-making are the first step in providing culturally sensitive palliative care. Palliative care team members continually expand awareness of their own biases and perceptions. Respectful acknowledgement of culturally sensitive support	Linguistic considerations; health literacy; culturally/socially sensitive care; cultural knowledge training; assessment of perception of illness	The Purnell Model of Cultural Competence (Long, C. O., 2011)
Domain 7: Care of the Patient Nearing the End of Life
Highlights the care provided near the end of life, with emphasis on the days leading up to and just after the death of a patient. Care team must ensure reliable access and attention in the days before death, and provide education about what to expect near death, as well as immediately following the death. Should introduce hospice as an option for support early	Assessment/management/recognition of near-death symptoms; bereavement; review of Advance Care Planning to ensure wishes are being delivered	The Caregiving Trajectory Among Poor and Chronically Ill People (Robles-Silva, L.,2008) Caregiving changes over time, moves from semi care to care of individual during “dying” phase
Domain 8: Ethical and Legal Aspects of Care
Palliative care team applies ethical principles to the care of patients with serious illness, including honoring patient’s care preferences, as well as decision made by legal proxies or surrogate decision-makers. Ensure surrogates’ obligations are to represent the patient’s preferences or best interests. Familiarity with local and state laws is needed relating to advance care planning and decisions regarding life-sustaining treatments	Resolving ethical dilemmas and legal issues; support and guidance for surrogate decision makers; access to legal counsel; review of Advance Care Planning to ensure wishes are met	The Lee Geropalliative Caring Model (Lee, S. M., 2018) Priorities in achieving the person/family outcome of well-being should include aligning care with goals/preference, Nonmaleficence, Beneficence, Facilitation of transitions, Fidelity as ethical principle that guides each domain

Results

Study selection

A total of 2,231 citations were retrieved; 44 articles met eligibility criteria and were included in this review. The PRISMA flow diagram is presented in Figure 1.

Figure 1.

PRISMA flow diagram

Study characteristics

The individual framework descriptions are available in Table 2. Articles were published between 2001 and 2019 with the majority of studies (n = 27, 61.4%) published within last 10 years.(22–48) Included studies were conducted in 9 different countries; the United States (n = 23, 52.3%),(22, 24, 26, 27, 30, 36–38, 41, 45, 49–61) Canada (n = 7, 15.9%),(23, 28, 33, 35, 42, 48, 62) United Kingdom (n = 6, 13.6%),(25, 31, 32, 44, 47, 63) Australia (n = 3, 6.8%),(29, 39, 40) and one each (2.3%) from Thailand,(43) Singapore,(34) Ireland,(64) Italy,(46) and Mexico.(65) Further information on study design and care settings are provided in Appendix 2.

Table 2.

Framework Name, Description and CPG domain by Study

Author, Year	Framework Name	Framework description (bolded terms indicate CPG keywords)	CPG Domain
Curtis, J., 2001	Conceptual model of physicians’ skills at providing high quality End-of-Life care	Doctor oriented framework with 12 components: accessibility and continuity; team coordination and communication; communication with patients; patient education; inclusion and recognition of the family; competence; pain and symptom management; emotional support; personalization; attention to patient values; respect and humility; and support of patient decision making. Includes 55 specific components of physicians’ skills	1
Hollen, P., 2004	Lung Cancer Symptom Scale-Meso Conceptual Model⁺	Patient oriented framework with 3 components: physical (symptoms and distress), functional (global activity status and physical, cognitive and social role), and quality of life (global quality of life -cognitive, psychologic, social, spiritual)	2,3,4,5
Jerant, A., 2004	The TLC model of Palliative Care	System oriented framework with 3 components: T (timely/team oriented), L (longitudinal), C (collaboration/comprehensiveness)	1
Nolan, M., 2004	A conceptual framework for End-of-Life care⁺	Patient oriented framework with spiritual components at the core of other psychological, physical and functional domains, as internal subcomponents influencing integrity of the person. External subcomponents are professional/organizational subcomponents	1,2,3,5
Tang, W., 2004	Conceptual model of quality and outcomes of care of terminally ill patients⁺	Patient oriented framework with 4 components, spirituality, pain, physical performance and social support	2,4,5
Nolan, M., 2006	Senses Framework	Patient oriented framework with 6 components: sense of security, belonging, continuity or connection, purpose, achievement and significance	5
Ayers, T., 2007	A partnership in ‘like-minded thinking’	Patient-Caregiver oriented framework with 4 components: reciprocating emotional attitude of hopefulness in partnership, mutual agreement of goal, reciprocal encouragement and sense of hopefulness	4,5
Hebert, R.S., 2007	The stress process model	Caregiver oriented framework with 2 components: stressor and appraisals (a person’s subjective reaction to stressors). Subcomponents includes demographic and illness characteristics, social support, personality attributes, coping styles, and cultural beliefs	4,6
Yedidia, M.J., 2007	A conceptual model of physician-patient relationships*	Patient-Doctor oriented framework with 5 components: range of need addressed, source of authority, maintenance of trust, emotional involvement and expression of authenticity	1,4
Kwak, J., 2008	Behavioral model of health service utilization*	System oriented framework with 3 components related to use of health services: social forces affecting the propensity of healthcare use, family and economic resources, Illness level or need for care	4
Potter, C., 2008	The six senses framework*	Patient oriented framework with 6 components: sense of security, belonging, continuity or connection, purpose, achievement and significance	5
Robles-Silva, L., 2008	The stages of caregiving trajectory⁺	Caregiver oriented framework with 3 phases of end-of-life care trajectory: semi-care, care, and dying	7
Bern-Klug, M., 2009	A framework for categorizing social interactions related to End-of-Life Care	Patient-System oriented framework with 5 components that classify the social interactions related to dying status: dying allowed, dying contested, mixed message dying, not dying, and not enough information	4
Buck, H. G., 2009	End-of-Life conceptual Model of the Geriatric Cancer Experience⁺	Patient oriented framework with 4 components that influence cancer experience at end-of-life: fixed characteristics of the patient (clinical status, physiologic, psychological, and spiritual domain), modifiable dimensions of patients’ experiences (including spirituality), Potential interventions provided, and quality of life as an outcome of interest	2,3,5
Ko, E., 2009	Health Belief Model*	Patient oriented framework with 4 components in preventive behavior: perceived susceptibility of health problem, perceived severity of consequences, perceived benefits in a preventive behavior, perceived barriers in engaging in preventive behaviors	5
Kongsuwan, W., 2009	Model of promoting peaceful death⁺	Patient-Nurse oriented framework with 2 components in promoting peaceful death: interaction to create comfort and atmosphere of nonattachment	4
Payne, S. A., 2009	End-of-Life care for Older People	System oriented framework with 4 components in the transition of care from life to death are knowing and revealing needs, expressing values and preferences, interacting with others and developing knowledge	1,4,7
Kelley, A. S., 2010	Model of factors affecting treatment intensity for patients with serious illness	Patient oriented framework with 2 components influencing treatment intensity: region & physician determinants (regional supply/resources, local practice pattern, individual practice pattern, physician characteristics) and patient & family determinants (financial, perceived benefit, communication, preference, characteristics of family and of patient)	1,4,5
Veillette, A.M., 2010	Good rural death	Patient oriented framework with 4 components: physical, emotional/psychological, social and spiritual	2,3,4,5
Zafar, S. Y., 2010	Conceptual model for the assessment and implementation of palliative and supportive care guidelines	System oriented framework with 3 components to achieve improved quality of life: education of practitioners and patients, quality assurance & utilization measures, and collection of patient-reported outcomes	1
Fineberg, I.C., 2011	Theoretical model for family conferences	System oriented framework with 2 components for successful family conferences: structural planning (conference organization) and process of negotiation, personal stance and emotional work	1
Long, C. O., 2011	The Purnell Model of Cultural Competence*	System oriented framework with 7 components as primary characteristics of culture (age generation, nationality, race, color, sex, religion) and 13 subcomponents as secondary characteristics of culture (educational status, socioeconomic status, occupation, military status, political beliefs, urban versus rural residence, enclave identity, marital status, parental status, physical characteristics, sexual orientation, gender issues, and reason for migration)	5,6
Jonnalagadda, S.L., 2012	Self-Regulation Model	Patient oriented framework with 5 components as representation of the disease: identify (interpretation of symptoms and labels attached to illness), Timeline (duration and trajectory of illness), perceived cause, consequences and impact of illness, and control (extent to which illness can be controlled/cured)	6
Wright, D. K., 2012	McGill Model of Nursing*	Patient-Nurse oriented framework with 2 main components in End-of-Life care: transitions and readiness, and family-centered care	4
Penman, J., 2013	The relational model of spiritual engagement	Patient-Caregiver oriented framework with 6 components associated with spiritual engagement: personal transformation, human values of love, compassion and altruism, maintaining relationships, participating in religious practices, and culture	5,6
Hui, D., 2014	Understanding “supportive care”, “palliative care”, and “hospice care”	System oriented framework denoting “Hospice Care” is part of “Palliative Care “, which in turn is under the umbrella of “supportive care” structure	1
Li, H. C., 2014	Dignity at the End of Life	Patient oriented framework with 5 components influencing one’s dignity: valuing oneself, being valued by others, perception, distress, psychological support	3,5
Goodman, C, 2015	The Uncertainty Framework	System oriented framework with 3 components characterized by uncertainty in end-of-life caregiving: treatment uncertainty (prognostication, symptom management, wishes known, how quality of life defined and intervention duration) relational uncertainty (staff to staff, resident, other professionals and patient’s family) and service uncertainty (workforce availability, skill level, palliative care support, funding to source care, service responsiveness and equipment)	1,2,4
Sinuff, T., 2015	Geriatric Cancer Experience in End of Life	System oriented framework with 3 components of end-of-life communication: advance care planning, Goals of Care discussions/documentation, healthcare system that can support processes	1
Ho, A. H., 2016	Interpretive-systemic framework of End of Life integrated pathway⁺	System oriented framework with 3 components needed to enhance quality of life and promote death with dignity: regulatory empowerment (interdisciplinary teamwork, resource allocation, culture building, collaborative policy making), family-centered care(continuity of care, family care conference, partnership in care), and collective compassion (devotion in care, empathic understanding, compassionate actions)	1,4,5
Dayal, A., 2017	Palliative Care discussion in Multiple System Atrophy patients	Patient-Doctor oriented framework with 2 components for palliative care discussions: palliative principles of care to be introduced by the neurologist and documenting discussions	1
Kim, K., 2018	Framework for individual and family End-of-Life decision making	System oriented framework with 6 components for decision making: communication, negotiation of decision-making, characteristics of decision maker, goals of care decision making, options and alternatives, and outcomes	1
Ladin, K. B, 2018	Nutbeam’s Health Literacy Framework*	Patient oriented framework with 3 components in patient’s literacy skills and comprehension: functional, interactive and critical literacy	6
Lee, S. M., 2018	The Lee Geropalliative Caring Model⁺	Patient-Nurse oriented framework with 4 components in ensuring one’s well-being are: aligning care with goals and preference, nonmaleficence, beneficence through comforting mind/body/spirit, Facilitation of transitions, fidelity as ethical principle that guides each domain	1,2,3,5,8
Philip, J. C., 2018	Framework of supportive and palliative care for people with high-grade glioma	System oriented framework with 5 components to address unmet needs of patients: coordination; repeat assessment; staged information according to transition reached; proactive response and referral systems; specific enquiry of patients and caregivers concerns	1
Philip, J. C., 2018	Palliative Care provision for patients with Chronic Obstructive Pulmonary Disease	System oriented framework with components for palliative care service delivery model for COPD (Chronic Obstructive Pulmonary Disease) patients: proactive response and referral system, respiratory care regarded as “usual care”, screening for physical/psychological symptoms, social and community support, provision of information, discussions around goals and preferences of care, transition to usual palliative care services	1,2,3,4,7
Sanders, J. J., 2018	The relationship between Communication and Goal-Concordant Care⁺	Patient-Doctor oriented framework with 4 components in end-of-life communication: information gathering, information sharing, responding to emotion and fostering relationship	1,4
Sinclair, S. J., 2018	Patient Compassion Model	Patient-Doctor oriented framework with 6 components of compassion: virtues, relational space, virtuous response, seeking to understand the patient as a person and their needs, relationship communication, attending needs/support provision	4,5
Thiamwong L., 2018	Thai Healthy Aging Model	Patient oriented framework with 3 components in healthy aging: normality, nature, dharma (a spiritual aspect of Buddhism)	5
Daley, S., 2019	Conceptual Framework for the Quality of Life of family carers of people with dementia*	Caregiver oriented framework with 3 components: from the person with dementia (quality of the relationship with / feelings towards the person with dementia, change in the person with dementia, and demands of caregiving), from within the carer (personal freedom, finding meaning, acceptance of the role, carer health, future planning), and from the external environment (support, weight of responsibility, family and social networks, role conflict)	2,3,4,5
Gazaway, S., 2019	Conceptual model of the chronic illness continuum with the phases of palliative care for minority populations	System oriented framework with 3 components in early palliative care, episodic palliative care, and late palliative care	1,2,7,8
Gonella S., 2019	A conceptual model of good end-of-life care in the nursing home context according to family carers’ perspective	Patient-system oriented framework with 4 components levels: resident functional triggers, patient-centered environments, care planning discussions, and palliative care approaches at the resident and family levels	1,2,4,8
Watson, J., 2019	Senses Framework*	Patient oriented framework with 6 components: sense of security, belonging, continuity or connection, purpose, achievement and significance	5
Zimmerman, C., 2019	Conceptual Framework for Team-Based Outpatient Early Palliative Care	System oriented framework with 2 components: principles of care (family-centered, patient-led, attentive, flexible) and domains of care (coping and support, symptom control, decision-making, future planning)	1,2,3,4,8

Sample Characteristics

Across studies, the total number of participants was 33,801 (min = 1, mean = 1,468, max = 30,765). The median number of study participants was 43. Eighteen articles were protocol or model development papers, which did not include empiric data. In the studies that did provide age-related information, the participant’s age ranged between 19 and 101 (median age = 60).(23, 25, 29, 31, 35, 37, 42–44, 47, 50–52, 54–57, 60, 65, 66) Slightly more than half were female (n = 987, 56.6%) in these studies.

Aim 1: Identify and Characterize the Frameworks

Origins of the Frameworks

New frameworks:

Investigators from 26 of the 44 studies (59.1%) proposed previously unpublished frameworks. Equal numbers of these new frameworks presented framework components that were derived from comprehensive reviews of published literature,(22, 24, 30, 32, 38, 40, 45, 46, 48, 55, 62) or qualitative studies (n = 11 respectively).(25, 29, 31, 36, 39, 42–44, 50, 52, 67) Other component generating methods included retrospective chart review of a specific patient population to examine current practices in Advance Care Planning and palliative care delivery,(35) survey and interviews of patients and health care staff combined with findings from literature,(64) and one Delphi study.(33) In one particularly interesting example,(49) a new framework titled “Promoting Peaceful Death” was developed, in which the components were drawn from multiple data sources such as Buddhist philosophy, an existing theory of “Peaceful End of Life”, a stakeholder interview (e.g. a Thai nurse), and a comprehensive review of relevant literature.

Existing Frameworks:

Eight of 44 investigators (18.2%) used existing frameworks. In most cases, existing frameworks were used to guide study designs, (37, 47, 56, 57, 61) or describe study topics.(26, 28, 63) For example, Wright and Gros,(28) used the McGill Model of Nursing framework to develop nursing practices specific to end-of-life care among terminally ill older cancer patients.

Adapted/Modified Frameworks:

Ten studies (22.7%) adapted or modified versions of existing frameworks. Adaptations were generally made to overcome inherent limitations of existing frameworks,(51, 59) and/or to tailor frameworks for specific study populations (e.g., terminally ill patients residing in hospice, terminal cancer patients).(27, 34, 53, 54, 58, 60, 65, 68) For example, in Buck and colleagues’ framework validation study,(51) an existing framework, the Framework of a Good Death,(69) was significantly modified and then renamed, the Geriatric Cancer Experience in EoL (end-of-life), which was subsequently tested with an existing dataset.

Orientations of the Framework

The framework orientation was identified by who or what was the subject of the framework. There were 8 orientations identified among the 44 frameworks we reviewed. In descending order, system-oriented frameworks were most commonly observed (n = 15, 34.1%),(24–26, 30, 32–34, 36, 39, 40, 45, 48, 55, 57, 64) followed by patient-oriented frameworks (n = 14, 31.8%).(22, 23, 27, 31, 37, 43, 47, 51, 54, 56, 58–60, 63) Four (9.1%) were patient-doctor oriented,(35, 41, 42, 61) followed by patient-nurse (n = 3, 6.8%),(28, 38, 49) caregiver, (44, 53, 65) patient-caregiver (4.5%),(29, 62) patient-system (4.5%),(46, 50) and doctor oriented (2.5%).(52) Examples of each of these orientation types are presented starting with the individual (e.g. patient) and working outwards to the system level.

Patient oriented frameworks:

These frameworks consist of components and sub-components that are relevant to palliative care patients. For instance, Thaimwong and Pungchompoo, proposed a new framework, Embedding Palliative Care into a Healthy Aging, which includes three major patient oriented components - normality (e.g., feeling like “a normal person”), nature (e.g., getting back to one’s normal living) and dharma (practicing one’s religion, Buddhism) to maximize the individual patient’s quality of life and promote a good death. Health care settings could use this framework during the design phase of a new program to incorporate elements which help their patients feel normal, recapture their patterns of life, and tap into their spirituality.

Patient-Caregiver relationship-oriented framework:

Two frameworks were identified as patient-caregiver relationship oriented.(29, 62) Ayers’(62) framework emphasized three components (i.e., a relationship, a shared goal with mutual agreement to work toward that goal, and reciprocal encouragement between patient-caregiver) with the outcome, hopefulness in one’s cancer care trajectory. Similarly, Penman’s framework, The Relationship Model of Spiritual Engagement, supports spiritual engagement to strengthen the patient and caregiver relationship by sharing their thoughts, beliefs, fears and vulnerabilities.(29)

Patient-Doctor oriented framework:

These frameworks were related to communication and relationship building. Sanders and colleagues,(41) used a literature review and an existing framework of patient participation in medical encounters,(70) to frame the relationships between patient-doctor communication, goal-concordance care and patient/caregiver experience. In a second example, Yedidia’s modified framework encompasses five components of patient-doctor relationships that can promote patient-centered end-of-life care; range of needs addressed, source of authority, maintenance of trust, emotional involvement and expression of authenticity.(61)

Patient-Nurse oriented framework:

Frameworks identified as patient-nurse oriented addressed collaboration, and emphasized trusting relationships.(28, 38, 49) For example, Wright and Gros described the McGill Model of Nursing which positions the nurses as a supporter, partner, and a learner to patients who are experiencing end-of-life care journey.(28)

Patient-System oriented framework: involved the interface of patients with long-term care:

Gonella and colleagues’ (46) framework of Good EoL care in the Nursing Home contexts models the patient-related (e.g., functional decline) and system-related (e.g., home care environment, institutional policies) triggers in the end-of-life care journey for the nursing home residents.

Caregiver oriented framework:

These frameworks consist of components pertinent to caregiver well-being,(44, 53) or the caregiving trajectory.(65) Daley and colleagues(44) used qualitative interviews and focus group discussions with family caregivers and staff from dementia care facilities. Factors (e.g., stressors and mediators) that either independently or collectively influence caregiver’s overall quality of life were identified, and a new framework titled Factors Influencing QoL (Qualify of Life) was proposed.

Doctor oriented framework:

Curtis and colleagues interviewed patients living with serious illnesses, their families, and healthcare workers to identify doctor-related factors that contribute to quality end-of-life care. This informed a new framework, of doctor-oriented skillsets inclusive of doctors’ communication skills (i.e., communication with patient, and inclusion/recognition of family) as well as affective skills (i.e., emotional support and personalization).

System oriented frameworks:

Frameworks that were identified as having system-orientation were related to implementation and delivery of palliative care services,(24, 25, 34, 36, 39, 40, 45, 48) definition/ concepts and models of palliative care,(30, 55, 64) or utilizations and evaluations of palliative care/ end-of-life care services.(32, 33, 57) A new framework, proposed by Zafar and colleagues,(24) is an example of a system-oriented framework. This framework was designed to assist implementation and delivery of guideline-based palliative care services in oncology setting, resulting in improved patient outcomes (e.g., quality of life) among cancer patients.

Aim 2: CPG Domains Addressed in the Frameworks

Twenty-one studies (47.7 %) covered a single CPG domain; the rest, two or more (n = 23, 52.3%). Please see Table 3 for further information.

Table 3.

Framework Adjudication by CPG Domain for each Study

CPG Domain	Curtis, J,2001	Hollen, P,2004	Jerant, A., 2004	Nolan, M., 2004	Tang, W,2004	Nolan, M., 2006	Ayers, T., 2007	Hebert, R. S,2007	Yedidia, M. J.,2007	Kwak, J., 2008	Potter, C., 2008	Robles-Silva, L.,2008	Bern-Klug, M,2009	Buck, H. G.,2009	Ko, E., 2009	Kongsuwan, W., 2009	Payne, A. S., 2009	Kelley, A. S.,2010	Veillette, A. M,2010	Zafar, S. Y,2010	Fineberg, I. C,2011	Long, C. O,2011	Jonnalagadda, S. L.,, 2012	Wright, D. K., 2012	Penman, J.,2013	Hui, D., 2014	Li, H. C., 2014	Goodman, C., 2015	Sinuff, T,2015	Ho, A. H,2016	Dayal, A,2017	Kim, K., 2018	Ladin, K. B,2018	Lee, S. M., 2018	Philip, J. C.,, 2018	Philip, J. C.,, 2018	Sanders, J. J., 2018	Sinclair, S. J.,, 2018	Thiamwong, L.,2018	Daley, S., 2019	Gazaway, S., 2019	Gonella S. 2019	Watson, J., 2019	Zimmermann, C., 2019
1	X		X	X					X								X	X		X	X					X		X	X	X	X	X		X	X	X	X			X	X	X		X
2		X		X	X									X					X									X						X		X				X	X	X		X
3		X		X										X					X								X							X		X								X
4		X			X		X	X	X	X			X			X	X	X	X					X				X		X						X	X	X			X	X		X
5		X		X	X	X	X				X			X	X			X	X			X			X		X			X				X				X	X				X
6								X														X	X		X								X
7												X					X																			X				X
8																																		X						X	X	X		X

Note: Domain 1: Structure and Processes of Care; Domain 2: Physical Aspects of Care; Domain 3: Psychological and Psychiatric Aspects of Care; Domain 4: Social Aspects of Care; Domain 5: Spiritual, Religious, and Existential Aspects of Care; Domain 6. Cultural Aspects of Care; Domain 7: Care of the Patient Nearing the End of Life; Domain 8: Ethical and Legal Aspects of Care

Single CPG Domain

If a framework was adjudicated as targeting a single CPG domain (n = 21, 47.7%), most included Domain 1: Structure and Process of Care (n = 9, 42.9%) followed by Domain 5: Spiritual, Religious, and Existential Aspects of Care (n = 5, 23.8%), Domain 4: Social Aspects of Care (n = 4, 19.0%), Domain 6: Cultural Aspects of Care (n = 2, 9.5%), and Domain 7: Care of the Patient Nearing the End of Life (n = 1, 4.8%). There was no framework that addressed Domains 2 (Physical Aspects of Care) or Domain 3 (Psychological and Psychiatric Aspects of Care) as a stand-alone domain. Definitions and specific details are provided below in descending order.

Domain 1. Structure and Process of Care (Palliative care be integrated into any health care setting and be delivered by interdisciplinary team with necessary qualifications and training of medical providers):

Most frameworks in this domain (n = 7 out of 9) described procedures and policies related to palliative care practice. These include frameworks informing model of palliative care/ palliative care delivery,(24, 30, 39, 55) family engagement/communication,(25, 36) and doctor’s qualifications/trainings.(52)

Domain 5. Spiritual, Religious, and Existential Aspects of Care (Spirituality as a fundamental aspect of compassionate, patient/family-centered palliative care):

Frameworks in this domain (n = 5) included components concerned with existential aspects of one’s end-of-life care journey (e.g., feeling of belonging, significance and connected),(47, 56, 58, 63) followed by the integration of one’s faith/spirituality/religious belief in the end-of-life care received.(43)

Domain 4. Social Aspects of Care (Palliative care addresses environmental and social factors that affect patient and family functioning and quality of life):

Four frameworks included components targeting social interactions,(50) social factors and supportive interaction that can enhance quality of life during the end-of-life care journey.(28, 49, 57) For instance, Kongsuwan and Touhy presented a new framework,(49) which emphasized the importance of social interactions among the three components (i.e., nurse, a dying patient and family which are required to achieve peaceful death for Thai Buddhists who are approaching death/ end-of-life).

Domain 6. Cultural Aspect of Care (Assessing and respecting values, beliefs and traditions related to health, illness, family caregiver roles and decision-making are the first step in providing culturally sensitive palliative care):

Two studies utilized existing frameworks to examine cultural aspect of care. For example, Jonnalgadda and colleagues utilized the self-regulation model to examine the racial and ethnic differences in one’s beliefs/perceptions of lung cancer diagnosis and how it attributes to palliative care services use.(27)

Domain 7. Care of the Patient Nearing the End of Life (The care provided near end-of-life, with emphasis on the days leading up to and just after the death of a patient):

Only a single study featured a framework that described the care of frail elderly persons approaching end-of-life. Robles-Silva’s framework links different phases in caregiving of a dying patient, from the initial care phase to the days leading up to the death of a patient.(65)

Multi-CPG domain

Twenty-three (52.3%) frameworks incorporated components of two or more CPG domains. There were 17 different combinations observed among multi-CPG domain featured in frameworks. The minimum number of CPG Domains were 2 domains per framework, (n = 8, 34.78%) with a maximum of 5 domains (n = 3, 13.0%). See Table 3 for specific domains and their grouping by study.

When the framework was classified as patient-oriented (n = 6 out of 23 multi-CPG domain studies), it always contained Domain 5 (Spiritual, Religious and Existential Aspects of Care). Domains 2 and 3 (Physical Aspects of Care and Psychological and Psychiatric Aspects of Care) were present in most (n = 5 out of 6 patient oriented studies, 83.3%) multi-CPG domain frameworks. In the eight multi-CPG frameworks that were system oriented, Domain 1 (Structure and Process of Care) was almost always present (n = 7 out of 8 system-oriented studies, 87.5%). The only system oriented study that did not include Domain 1 was The Purnell Model of Cultural Competency,(26) which provided an in-depth look at cultural and spirituality within palliative care delivery system.

Of three multi-domain frameworks that were patient-doctor oriented, Domain 4 (Social Aspects of Care) was always present (100%). In two of these studies, Domains 1 and 4 (Structure and Processes of Care, Social Aspects of Care) were also included (66.7%). Similarly, when framework was caregiver-oriented, Domain 4 (Social Aspects of Care) was always included (100%). There was only one framework that was patient-nurse oriented, the Lee Geropalliative Care Model. However, it represented the greatest number of CPG domains (i.e., Domains1, 2, 3, 5 and 8) apart from the system-oriented frameworks.

Discussion

The purpose of this comprehensive review of the palliative care literature had two aims. First, to identify and characterize conceptual or theoretical frameworks used in palliative care research studies and then secondly, to examine which domains from the Quality Palliative Care are addressed in each framework. To the best of our knowledge this is the first systematic review and examination of published palliative care frameworks.

What we found was encouraging, but also thought provoking. In the first case we found a robust set of palliative care frameworks (n = 44), which could be clearly linked to specific quality domains of importance to palliative care. In the second case we found a large number of frameworks which were used once (n = 26) or were system focused (n =15) rather than oriented towards the patient. We also found many that included only one CPG domain (n = 23) and CPG domains (Domain 2 and 3) were rarely addressed in any framework. The more thought-provoking findings will now be discussed in depth.

A little over half of the included studies (n=26) proposed a new conceptual framework, with its components and subcomponents derived from comprehensive literature review and/or qualitative interviews. However, we found little evidence of subsequent use of the framework by the original developers beyond the initial study. This suggests that frameworks are being developed to support a particular study without building the science by revising the framework, the concepts, and their relationships using data accrued during the study. When authors did utilize existing frameworks it was mainly for study design,(56) or electing the variables of the study(65). Similarly, when authors adapted or modified frameworks, it was generally to address specific study population (e.g., palliative care recipients),(34)or study settings (e.g., cancer centers)(37). Taken together this suggests a missed opportunity to build the science by focusing on testing and improving one model as has been done, for example, in primary care with the Chronic Care Model.(71–73)

Upon examining framework orientation, we found a total of 8 different types of orientation among 44 studies. This was a novel type of analysis resulting in new knowledge (i.e. palliative care framework orientation) which will hopefully help future investigators and clinicians choose an existing framework which suits their needs rather than creating one de novo. However, one third of the frameworks (n=15) were oriented towards systems (i.e., palliative care, end of life care systems), which denotes a heavy emphasis on the formation of interdisciplinary team structures and procedures/ protocols to meet qualifications of palliative care providers. These are all important areas; however, patient centered care calls us to move beyond the system level. Our search strategy did find several frameworks with relationship-focused orientations, namely, patient-doctor,(35, 41, 42, 61) patient-nurse,(28, 38, 49) and patient-caregiver.(29, 62) However, compared to systems orientation, relationship-based frameworks often addressed spirituality, psychological support/ support system, and partnerships denoting different CPG quality domains. This is understandable but calls into question how many domains should be included when assessing quality.

Finally, CPGs identify 8 domains found in high quality palliative care. When we conducted an across framework analysis of all included frameworks to adjudicate the CPG domains included in the framework, we found that 21 frameworks included only a single CPG domain, and the rest included two,(26, 29, 31, 41, 42, 53, 61, 62) to five domains.(38, 40, 48) No framework included all domains. Of frameworks that addressed a single domain, Domain 1. Structure and Processes of Care (n = 9) and Domain 5. Spiritual, Religious, and Existential Aspects of Care (n = 5) were most frequently mentioned. This suggests that when examined alone structural and existential areas have been examined more than other equally valuable areas such as physical and psychological aspects of care (Domains 2 & 3, respectively).

In frameworks that addressed two or more CPG domains, we found that, as in the single domain frameworks, Domain 5. Spiritual Religious and Existential Aspects of Care was most commonly included (n = 6). In previously published studies, it was shown that meeting spiritual needs is an intrinsic aspect of palliative care,(74) which is associated with positive patient care outcomes such as enhanced quality of life,(75) and ease of physical pain.(76) In terms of existential aspects of palliative care, it is an area that has received increasing attention over the past decade. Many studies show that individuals who are nearing the end of their life often experience varying degrees of existential anguish and distress which may become actual barriers to provision and receipt of timely palliative care when the person (or their family) refuses palliative care due to fear or stress.(77–80) The emerging interest in spiritual, religious, and existential aspects of care within palliative care frameworks is a positive sign that more attention is being placed in what constitute human suffering, beyond just physical pain. A last interesting finding in this domain analysis was the inclusion of more domains per framework across time. Prior to 2018 most of the frameworks included 1 to 3 domains but after 2018 there was an increase in the number of frameworks which included 4–5 domains. This inclusion of more domains possibly points to a more holistic approach as palliative care matures or it may be an artifact of the funding of more mechanistic studies.

Implications

Understanding the origin and orientation of the frameworks is important in advancing palliative care science as it provides information on the history (how the framework was derived) and focus (for whom the framework was derived). This enables both researchers and clinicians to quickly assess whether there is an existing framework which suggests a way forward for a research issue or clinical problem which they need to address. For example, in the past palliative care recipients were primarily cancer patients. However, currently the number of individuals suffering from multiple serious chronic illnesses who are in need of quality palliative is continually increasing. When a new palliative care program is being established clinicians will be able to use resources provided here to review multiple frameworks, identify the one most salient to their program and then utilize that framework to build their own program of quality palliative care.

Limitations

Certain things should be kept in mind while reviewing the findings in this paper. First, as with all review papers our findings are a function of our search terms, databases, and eligibility criteria. It is possible that other frameworks exist which were not captured in this search. However, use of best practices and engagement of a medical informationist should have somewhat mitigated this threat. Secondly, our synthesis was inherently a qualitative process. Other teams of investigators might have drawn different conclusions, but once again, we sought to mitigate this with transparently reporting all methods and study level data so that readers can examine the frameworks and our decision making for themselves.

Conclusion

In conclusion, this review examined the empiric palliative care literature to identify and characterize conceptual frameworks used in palliative care research studies. Once this was accomplished, we then examined the CPG domains addressed in each framework as a means to link these frameworks to established quality practices. What was found was many individualistic frameworks which address 1–2 domains. To advance both the science and practice of palliative care it is suggested that frameworks which have been tested outside of their original setting which included multiple CPG domains be used in any future research studies or practice change projects.

What is already known about the topic?

• Conceptual frameworks are used in palliative care research studies to help with study design, guide and conduct investigations

• With increased attention towards palliative care, there has been commensurate development of conceptual frameworks guiding research studies

What this paper adds?

• To date, there has not been a comprehensive review of existing palliative care conceptual frameworks, which identifies and characterizes them using a quality lens

• This study identifies the key components of each construct from included frameworks

• Careful examination of each frameworks identified (n = 44) to investigate which domains from the Clinical Practice Guidelines for Quality Palliative Care area addressed

Implications for practice, theory, or policy

• Understanding the origin and orientation of frameworks is important in advancing palliative care science as it provides information on the history and focus

• This information enables both researchers and clinicians to quickly assess whether there is an existing framework which suggests a way forward for a research issue or clinical problem which they need to address