The Lack of Standard Definitions in the Supportive and Palliative Oncology Literature

Abstract

Context

Multiple organizations have raised concerns about the lack of standard definitions for terminology in the supportive and palliative oncology literature.

Objectives

We aimed to determine: 1) the frequency of 10 commonly used terms in the supportive and palliative oncology literature; 2) the proportion of articles that provided definitions for each term; and 3) how each term was defined.

Methods

We systematically searched MEDLINE, PubMed, PsycINFO, the Cochrane Library, Embase, ISI Web of Science, and CINAHL for original studies, review articles and systematic reviews related to palliative care and cancer in the first six months of 2004 and 2009. We counted the number of occurrences for “palliative care,” “supportive care,” “best supportive care,” “hospice care,” “terminal care,” “end-of-life,” “terminally ill,” “goals of care,” “actively dying,” and “transition of care” in each article, reviewed them for the presence of definitions, and documented the journal characteristics.

Results

Among the 1213 articles found, 678 (56%) were from 2009. “Palliative care” and “end-of-life” were the most frequently used terms. “Palliative care,” “end-of-life” and “terminally ill” appeared more frequently in palliative care journals, while “supportive care” and “best supportive care” were used more often in oncology journals (P<0.001). Among 35 of 601 (6%) articles with a definition for “palliative care,” there were 16 different variations (21 of 35 articles used the World Health Organization definition). “Hospice care” had 13 definitions among 13 of 151 (9%) articles. “Supportive care” and other terms were rarely defined (less than 5% of articles that used the term).

Conclusion

Our findings highlight the lack of definitional clarity for many important terms in the supportive and palliative oncology literature. Standard definitions are needed to improve administrative, clinical and research operations.

Introduction

Palliative care has been defined by the World Health Organization (WHO) as an approach that “improves the quality of life of patients and their families facing the problem associated with life-threatening illness...”(1). Over the past few decades, palliative care has evolved from a philosophy of care to an accredited professional discipline, with a growing number of clinical programs and an accumulation of expertise related to symptom control, psychosocial and spiritual care, communication, decision making, and end-of-life care (2).

In contrast to many established disciplines such as medical oncology and infectious diseases, many commonly used terms in palliative care are poorly defined. According to the National Institute of Health (NIH) Conference Statement on Improving End-of-Life Care, “there has been a lack of definitional clarity related to several concepts and terms.... The lack of definition for the key terms represents a barrier to research in improving end-of-life care”(3). This deficiency was recently echoed by the American Society of Clinical Oncology (ASCO), which stated a “unanimous consensus regarding the need for... definitions of palliative cancer care...”(4).

In addition to operational terms, the definitions of many prognostic terms used in palliative care have not been standardized. How terminal is “terminally ill”? How close to the end of life is “end of life”? How about “actively dying”? A lack of consensus in the meaning of commonly used terms can have significant implications administratively, clinically and academically, resulting in miscommunications, misunderstandings, and mishaps.

To date, no study has specifically examined the frequency of use of palliative care terms, and how often the terms were defined. A clear understanding of the frequency of use and variations in definitions of these terms would underscore the need for standardization, which in turn could help minimize misinterpretation of these key expressions. In this literature review, we determined: 1) the frequency of 10 commonly used terms in the supportive and palliative oncology literature by journal type; 2) the proportion of articles that provided definitions for each term; and 3) how each term was defined.

Methods

Palliative Oncology Literature

The Institutional Review Board at M. D. Anderson Cancer Center provided approval to proceed without the need for full committee review. Details on how we identified and characterized the supportive and palliative oncology literature recently has been published (5). Briefly, publications were included if they were: 1) original studies, reviews or systematic reviews, 2) related to both palliative care and oncology, and 3) published in the first six months of 2004 or 2009. Non-English articles, commentaries, editorials, dissertations, conference abstracts and letters were excluded. A clinical librarian searched MEDLINE PubMed, PsycINFO, the Cochrane Library, EMBASE, ISI Web of Science, and CINAHL on October 28, 2009. To identify original studies or review articles related to supportive care or palliative care, we used the Boolean expression (Palliat$ or hospice$ or “terminal care”). This search strategy has previously been validated to achieve a specificity of 99.97% among general medical journals (6), and has been used in several other studies (7, 8). We then further identified studies related to cancer. Our librarian hand-picked the articles for the correct date of publication in ISI Web of Science and the Cochrane Library since these databases could not be limited by month of publication. Duplicates were removed.

A medical oncologist (D.H.) and an internist (H.P.), both with specialized research training in palliative care, reviewed each abstract independently for relevance to palliative oncology. All discrepancies were discussed and a final list of articles was compiled. We then obtained full electronic copies of all unique publications identified based on the above search strategy. For each publication, one author (D.H.) extracted information regarding study type (original, systematic review or review), year of publication, and journal type. When a journal type fell under multiple categories, we used a hierarchal approach for classification. For instance, a journal focusing on palliative care issues in oncology was classified as a palliative care/symptom control journal consistently.

Selection of Supportive and Palliative Oncology Terms

To identify the top 10 search terms for this study, we provided 20 palliative care specialists/oncologists, all with at least one year of clinical experience, with 18 terms: “actively dying,” “best supportive care,” “dying,” “end stage cancer,” “end-of-life,” “far advanced cancer,” “goals of care,” “holistic care,” “hospice care,” “impending death,” “near end-of-life,” “palliative care,” “seriously ill,” “supportive care/medicine,” “terminal care,” “terminally ill,” “transition of care,” and “specialist palliative care service.” We asked each participant to give a score between 1 and 5 regarding 1) How commonly is each term used in the palliative care literature?“ where 1=rarely and 5=frequently; and (2) “In your opinion, how important is it for the term to be defined?” where 1=not important and 5=very important. The two scores were combined. The 10 terms with the highest average scores were used for this study.

Frequency of Terms and Definitions

To count the number of occurrences of each term, we first retrieved Portable Document Format files of all manuscripts, converted them into text files, and imported them into Microsoft Access to search for key words using a Visual Basic for Applications script. For “palliative care” and “hospice care,” we also searched “palliative medicine” and “hospice medicine” and combined the search results. The bibliography, header, footer and acknowledgement sections were excluded from the counting process. For manuscripts that failed this process, we counted the terms manually. “Supportive care” and “best supportive care” were considered as two mutually exclusive terms.

For manuscripts with at least one occurrence of each term of interest, we manually reviewed them for counting accuracy and for the presence of a definition, which was determined based on whether the authors explained or identified the nature or essential qualities of the term. Any uncertainties regarding whether a statement represented a definition were discussed by two authors. In this study, a consensus in definitional clarity was defined when a majority (more than 50%) of the studies that included a definition used the same description.

Statistical Analysis

We summarized the publication characteristics using frequencies, percentages, medians and interquartile ranges. We compared the frequency of occurrence of each term by year (2004 vs. 2009) and journal type (palliative care vs. oncology vs. others) using the Chi-square test and Fisher’s exact test where applicable. A two-sided P-value of less than 0.05 was considered to be statistically significant. The STATA special edition software (version 10.0, StataCorp LP, College Station, TX, USA) was used for statistical analysis.

Results

Literature Characteristics

We identified a total of 1213 supportive/palliative oncology articles. The literature characteristics have been reported in detail previously (5). A total of 535 (44%) articles were from 2004 and 678 (56%) from 2009. Original studies totaled 848 (70%); 506 (41%) were published in palliative care journals, 225 (18%) in oncology journals, and 482 (40%) in other journals.

Identification of Terms

Based on 20 physicians’ perceived frequency of occurrence and the need for a definition, we identified 10 terms chosen for further examination (Table 1). The most common terms that appear in the supportive and palliative oncology literature were “palliative care,” “end-of-life” and “terminally ill.” Contrary to findings from the physician survey, “transition of care,” “actively dying” and “best supportive care” were not commonly used in the supportive and palliative oncology literature.

Table 1. Frequency of Occurrence and Definitions for Supportive/Palliative Oncology Terms (n=1213).

Term	Number of Articles Including the Term n (%)		Median Number of Occurrences/Articlea n (interquartile range)		Definition Presenta n (%)
Palliative care	601	(50)	6	(2-14.5)	35	(6)
End of life	386	(32)	4	(1-9)	0	(0)
Terminally ill	245	(20)	2	(1-5)	5	(2)
Hospice care	151	(12)	2	(1-4)	13	(9)
Supportive care	106	(9)	1	(1-3)	2	(2)
Terminal care	67	(6)	1	(1-2)	2	(3)
Goals of care	55	(5)	2	(1-4)	1	(2)
Best Supportive care	26	(2)	1	(1-2)	1	(4)
Actively dying	15	(1)	1	(1-2)	1	(7)
Transition of care	1	(0.1)	1	-	0	(0)

^aAmong articles with at least one occurrence of the term (i.e., second column)

Between 2004 and 2009, we found a significant increase in the frequency of occurrence for “palliative care” and “end-of-life,” but not for “supportive care” or the other terms (Table 2). We also found that “palliative care,” “end-of-life” and “terminally ill” appeared more frequently in palliative care journals, while “supportive care” and “best supportive care” were more often used in oncology journals.

Table 2. Frequency of Terms by Year and Journal Type^a.

	Year			Journal Type
Term	2004 n=535 (%)	2009 n=678 (%)	P-value	Palliative Care n=506 (%)	Oncolog n=225 (%)	Others n=152 (%)	P-value
	245	356	0.02	349 (69)	100 (44)	152	<0.001
Palliative care	(46)	(53)				(32)
	129	257	<0.001	198 (39)	64 (28)	124	<0.001
End of life	(24)	(38)				(26)
Supportive care	44 (8)	62 (9)	0.57	46 (9)	32 (14)	28 (6)	0.001
Best Supportive	12 (2)	14 (2)	0.83	0 (0)	18 (8)	8 (2)	<0.001
care
	106	139	0.77	133 (26)	34 (15)	78 (16)	<0.001
Terminally ill	(20)	(21)
Goals of care	22 (4)	34 (5)	0.46	24 (5)	11 (5)	21 (4)	0.94
Terminal care	32 (6)	35 (5)	0.54	25 (5)	7 (3)	35 (7)	0.06
Transition of care	1 (0.2)	0 (0)	0.26	0 (0)	0 (0)	1 (0.2)	0.49
Hospice care	64 (12)	87 (13)	0.65	71 (14)	26 (12)	54 (11)	0.37
Actively dying	6 (1)	9 (1)	0.75	8 (2)	0 (0)	7 (2)	0.17

^aThe Chi square test and Fisher’s Exact test (for small samples) were used.

Frequency and Nature of Definitions

“Palliative care” and “hospice care” were most frequently defined, with a definition found in 6% and 9% of articles that had at least one occurrence of each term, respectively (Table 1). We identified no definitions for “end-of-life” and “transition of care,” and the rest of the terms were rarely defined (<5% of articles that used the term, Table 1). Among all the articles that provided definitions for the 10 terms, we found only two that focused on definitional issues (9, 10).

Table 3 lists definitions for the 10 terms (10, 18, 26-74). Among the articles searched, we found a total of 16 different definitions for “palliative care” from 35 papers, with a majority of studies (21 of 35) that provided a definition for “palliative care” adopting the one formulated by the World Health Organization. In contrast, we found 13 different definitions for “hospice care” in 13 articles, and only two definitions for “supportive care” from two articles. “Terminally ill” was described as a prognosis of six months or less in four of five articles.

Table 3. Definitions from Supportive/Palliative Oncology Studies.

Palliative Care

14 articles used the 2002 World Health Organization definition:

“An approach that improves the quality of life of patients and their families facing the problems associated with life-threatening illness through the prevention and relief of suffering by means of early identification and impeccable assessment of pain and other problems, physical, psychosocial and spiritual.” (26-38)

6 articles used the 1990 World Health Organization definition:

“The active total care of patients whose disease is not responding to curative treatment.” (10, 39-44)

14 articles used other definitions:

“The active holistic care of patients with advanced, progressive illness.” (45) “Care devoted to improving quality of life and reducing suffering for patients with severe, life threatening illnesses and their families.” (46) “Active overall care, including quality-of-life care, of patients whose disease is no longer responsive to medical treatment.” (47) “Care that aims to optimize the comfort, function and social support of the patients and their family when the illness is incurable.” (18) “Care given to patients with symptoms originating from incurable disease or with a progressive disease with short expected survival. Palliative care is an active, comprehensive care model built on a clearly defined philosophy with an aim to create the requirements for quality of life (QOL) when a cure is no longer possible.” (48) “Care focused on addressing physical, psychological, social, and spiritual domains in patients with progressive, life-limiting symptoms and their family.” (49) “Care... provided from the early phase of advanced disease.” (50) “The combination of active and compassionate therapies intended to comfort and support individuals and families who are living with or dying from a progressive, life-threatening illness.” (51) “As stated by the National Consensus Project, palliative care is ‘The goal is to prevent and relieve suffering and to support the best quality of life for patients and their families, regardless of the stage of the disease or the need for other therapies.’ Also described by the Center to Advance Palliative Care as, ‘Interdisciplinary care that aims to relieve suffering and improve quality of life for patients with advanced illness and their families.’”(52) “Defined by the American Academy of Hospice and Palliative Medicine as providing care ‘focused on alleviating suffering and promoting quality of life.” (53) “The RCPCH defined palliative care as ‘an active and total approach to the care of children, embracing physical, emotional, social and spiritual elements.’” (54) “The active holistic care of patients with advanced, progressive illness.” (55) “Medical care focused on relief of physical, emotional, and existential suffering and support for the best possible quality of life for patients and their family caregivers.” (56) “The active total care of the child’s body, mind, and spirit, and also involves giving support to the patient’s family.” (57)

Supportive Care

Defined by ESMO as “care that aims to optimize the comfort, function, and social support of the patients and their family at all stages of the illness, including those with curable cancer.”(18) “Interventions intended to manage the adverse effect of the tumor itself and antineoplastic therapy.” (58)

Best Supportive Care

“Watchful-waiting, or best supportive care, is meant to enhance or maintain the patient’s quality of life with treatments that are symptom-focused rather than tumour-focused.” (59)

Hospice Care

“A programmatic model for the delivery of palliative care at the end-of-life that primarily serves administrative, regulatory and cost-containment interests.” (10) “A program for terminally ill persons providing services for the palliation and management of terminal illness and related conditions.” (60) “Hospice services provide supportive care in the home for patients with a life expectancy of less than 6 months. The focus of hospice care is patient comfort; treatment to extend life is not included.” (61) “Designed to provide a variety of services to terminally ill patients, primarily focusing on pain relief and symptom management.” (62) “Supports patients through the dying process and the surviving family members through the dying and bereavement process.” (32) “In providing active care of patients with advanced, progressive, and incurable disease, hospice care: Provides relief from pain and other distressing symptoms; Enhances quality of life when the length of life is limited; Regards dying as a normal process; Does not intend to hasten or postpone death; Incorporates psychological and spiritual aspects of patient care; Uses a team approach to provide a support system for patients and their families.” (63) “Provides terminally ill patients with a unique set of benefits, services, and support. Its goal is neither to prolong life nor hasten death, but rather to provide total care that maximizes quality of life.” (64) “Provides palliative and passionate care for people in the last phases of a terminal disease and their families, so that they may live with dignity and as fully and comfortably as possible.” (65) “A multidisciplinary program designed to increase the quality of life for a person at the end of life but does not require that the patient be in a do not resuscitate status. This program can be administered where the patient chooses, that is, a nursing home, the home of a relative, or in their own home. Types of support offered may include medical, emotional, spiritual, and therapy. Often, a component is offered for the family of the patient, which can include counseling, bereavement help, support groups, and training in how to care for their loved one.” (66) “Designed for patients with terminal illness and a life expectancy of 6 or fewer months. To be eligible for hospice, patients must be willing to forgo treatment of the condition for which hospice was initiated (e.g., a cancer patient cannot receive cancer-directed therapy, such as chemotherapy, while enrolled in hospice). Hospice provides services to reduce pain and suffering and to improve quality of life. Hospice includes typical palliative care services, such as pain and symptom management, and also offers more comprehensive services, such as medications for pain and symptom management, case management, respite care, and bereavement services. Hospice care is provided by an interdisciplinary team that includes a nurse, physician, social worker, chaplain, home health aide, and volunteers.” (67) “Involves a team-oriented approach for providing emotional and spiritual support for the patient and family, as well as offering expert medical care and pain management.” (68) “A Medicare-sponsored program that elderly and non-elderly patients can enter for the last 6 months of their lives.” (69) “A comprehensive program of care that is appropriate when patients with chronic, progressive, and eventually fatal illness are determined to have a prognosis of 6 months or fewer.” (70)

End of Life

No definitions

Terminally Ill

“A life expectancy of 6 months or less.” (10) “Beneficiaries who have a progressive incurable illness that will culminate in death.” (71) Two definitions mentioned in this article: “Life expectancy less than three months;” “Life expectancy of less than six months.” (41) “Less than six months to live.”(72) “Death is likely within 6 months.” (56)

Goals of Care

“Related to quality of life and end-of-life care.” (49)

Terminal Care

“Care of patients with an anticipated prognosis of 3 months or less.” (73) “Concerns individuals with a terminal diagnosis, from which death can be expected within 12 months. Palliative terminal care concerns relieving the patients’ suffering in the last phase of their lives, and includes, in addition to alleviation of physical symptoms, attention to emotional, spiritual and social aspects.” (41)

Transition of Care

No definitions

Actively Dying

“The hours or days preceding imminent death during which time the patient’s physiologic functions wane.” (74)

Discussion

In this literature review, we found that many supportive and palliative oncology terms were rarely and inconsistently defined. Our findings highlight the lack of definitional clarity for these terms in the literature. Standard definitions are urgently needed to improve administrative, clinical and research operations.

Although it would be impractical to define every term that appears in a manuscript, it is generally considered good practice to clarify a term’s meaning when it is poorly understood or has many different interpretations. The 10 terms in this study were selected by practicing physicians to meet the aforementioned criteria. Indeed, we found that many terms were rarely defined. In contrast, “palliative care/medicine” had 16 variations of definitions in 35 articles and “hospice care/medicine” had 13 different definitions in 13 articles. Consistent with our findings, Pastrana et al. examined the terms “palliative medicine” and “palliative care” on the World Wide Web and in medical reference books, and found 37 English and 26 German definitions (11). Until standardized definitions exist, our results suggest that there is a need to include a definition within each article that uses the term.

We found that “palliative care” was more commonly used in the literature as compared to “supportive care.” In fact, the use of “palliative care” has increased over time, while the frequency of “supportive care” has remained about the same. The former term was used more in palliative care journals, and the latter was found in oncology journals. There has been a lot of debate regarding the meaning and utilization of these two terms (9, 12-14). The National Cancer Institute (NCI) defines “palliative care” and “supportive care” synonymously (Table 4) (15). This was supported by a high degree of overlap in the definitions for these two terms as shown in our study (Table 3). Specifically, both “palliative care” and “supportive care” involved multidimensional, interdisciplinary care aimed at improving the quality of life of patients and families throughout the entire trajectory of illness. In contrast, others viewed “palliative care” as serving the needs of patients with incurable illness, whereas “supportive care” provides care for patients earlier in the disease trajectory (16). Two recent studies revealed that “palliative care” and “supportive care” were perceived differently among clinicians and caregivers (17, 18), with an accompanying editorial providing an insightful review of the many issues related to selection of the appropriate terminology (9).

Table 4. Definitions of Palliative Care and Supportive Care by Various Organizations.

Palliative Care Definitions

American Association of Hospice and Palliative Medicine (AAHPM) (75)

“The goal of palliative care is to prevent and relieve suffering and to support the best possible quality of life for patients and their families, regardless of the stage of the disease or the need for other therapies. Palliative care is both a philosophy of care and an organized, highly structured system for delivering care. Palliative care expands traditional disease-model medical treatments to include the goals of enhancing quality of life for patient and family, optimizing function, helping with decision-making and providing opportunities for personal growth. As such, it can be delivered concurrently with life- prolonging care or as the main focus of care.”

American Society of Clinical Oncology (ASCO) (4)

“The integration into cancer care of therapies that address the multiple issues that cause suffering for patients and their families and impact their life quality.”

European Association for Palliative Care (EAPC) (76)

“The active, total care of the patients whose disease is not responsive to curative treatment. Control of pain, of other symptoms, and of social, psychological and spiritual problems is paramount. Palliative care is interdisciplinary in its approach and encompasses the patient, the family and the community in its scope. In a sense, palliative care is to offer the most basic concept of care – that of providing for the needs of the patient wherever he or she is cared for, either at home or in the hospital. Palliative care affirms life and regards dying as a normal process; it neither hastens nor postpones death. It sets out to preserve the best possible quality of life until death.”

European Association of Medical Oncology (ESMO) (77)

“Care that aims to optimize the comfort, function, and social support of the patients and their family when cure is not possible. This dimension of care emphasizes the special needs of patients whose illness is either incurable or unlikely to be cured. Needs include physical and psychological symptom control, education, and optimization of community supports.”

International Association for Hospice and Palliative Care (IAHPC) (78)

“Care of patients with active, progressive, far-advanced disease, for whom the focus of care is the relief and prevention of suffering and the quality of life.”

National Comprehensive Cancer Network (NCCN) (79)

“Both a philosophy of care and an organized highly structured system for delivering care to persons with life-threatening or debilitating illness. Palliative care is patient and family centered care that focuses on effective management of pain and other distressing symptoms, while incorporating psychosocial and spiritual care according to patient/family needs, values, beliefs, and cultures.”

National Cancer Institute (NCI) (80)

“Care given to improve the quality of life of patients who have a serious or life- threatening disease. The goal of palliative care is to prevent or treat as early as possible the symptoms of a disease, side effects caused by treatment of a disease, and psychological, social, and spiritual problems related to a disease or its treatment. Also called comfort care, supportive care, and symptom management.”

National Hospice and Palliative Care Organization (NHPCO) (81)

“Treatment that enhances comfort and improves the quality of an individual’s life during the last phase of life.”

National Palliative Care Research Center (NPCRC) (82)

“Focuses on relieving suffering and achieving the best possible quality of life for patients and their family caregivers. It involves symptom assessment and treatment; aid with decision making and establishing goals of care; practical support for patients and their family caregivers; mobilization of community support and resources to assure a secure and safe living environment; and collaborative and seamless models of care (hospital, home, nursing homes, and hospice). It is offered simultaneously with life prolonging and curative therapies for persons living with serious, complex, and eventually terminal illness.”

World Health Organization (WHO) (1)

“An approach that improves the quality of life of patients and their families facing the problem associated with life-threatening illness, through the prevention and relief of suffering by means of early identification and impeccable assessment and treatment of pain and other problems, physical, psychosocial and spiritual.”

Supportive Care Definitions

European Association of Medical Oncology (ESMO) (77)

“Care that aims to optimize the comfort, function, and social support of the patients and their families at all stages of the illness. This dimension of care emphasizes the oncologist’s role in optimizing the quality-of-life for all patients, including those with potentially curative illness.”

Multinational Association of Supportive Care in Cancer (MASCC) (83)

“Supportive Care in cancer is the prevention and management of the adverse effects of cancer and its treatment. This includes management of physical and psychological symptoms and side effects across the continuum of the cancer experience from diagnosis through anticancer treatment to post-treatment care. Enhancing rehabilitation, secondary cancer prevention, survivorship and end of life care are integral to Supportive Care.”

National Cancer Institute (NCI) (80)

“Care given to improve the quality of life of patients who have a serious or life- threatening disease. The goal of supportive care is to prevent or treat as early as possible the symptoms of a disease, side effects caused by treatment of a disease, and psychological, social, and spiritual problems related to a disease or its treatment. Also called comfort care, palliative care, and symptom management.”

There are many reasons why standardized definitions are lacking for many palliative care terms. First, unlike many established disciplines, palliative care is still trying to find its own identity within the health care system (10). Second, the multidisciplinary nature of palliative care means that there is a plethora of viewpoints and perspectives from different professional organizations. Third, some of the terms such as “palliative care” can be interpreted as a philosophy, concept, approach, program, service, specialty or knowledge domain (19). The pleomorphic nature invites diverse interpretations. Fourth, the sensitive nature of palliative care has led to creative list of euphemisms over time (12). There appears to be an increased interest in adopting the term “supportive care.” A recent study found an increase in service utilization when our Palliative Care Program changed its name to “Supportive Care” (20). Fifth, significant regional variations in the structures and processes of palliative care programs exist. For example, “hospice care” in United States involves mostly home care, whereas it represents an inpatient home-like setting in Canada and much of Europe. Finally, as evident in this study (Table 3), the loose use of language by authors also contributes to definitional heterogeneity.

The lack of standard definitions in supportive/palliative oncology can have negative implications administratively, clinically and academically. We recently conducted a survey of cancer centers in the United States, and found great variation in the structure of palliative care programs (21). Some palliative care programs have both inpatient and outpatient services, while others were only affiliated with a hospice program. The lack of definition also may hamper knowledge translation (22). Systematic reviews on the effectiveness of palliative care have not been conclusive. This may partly be caused by the inclusion of a heterogenous array of “palliative care” interventions, ranging from nurse-led follow-up programs to comprehensive interdisciplinary teams (23, 24). Finally, “best supportive care” has been conveniently used to describe control arms in oncology therapeutic trials that range from “no treatment” to variable degrees of supportive care services (13, 25).

How can we establish standardized definitions? We first need to gain a better understanding of how each term is used and defined in the literature. For system terms such as “palliative care,” it would be helpful to include in its definition the essential elements related to its structure, process and outcomes. Professional organizations such as WHO, ASCO, the European Society for Medical Oncology (ESMO), the American Academy of Hospice and Palliative Medicine (AAHPM), the European Association for Palliative Care (EAPC), and the International Association for Hospice and Palliative Care (IAHPC) all need to work together to arrive at a consensus and to publish standardized definitions. A list of definitions for “palliative care” and “supportive care” by various organizations is shown in Table 4 (1,4, 75-83).

This study has a number of limitations. First, our literature search was limited to cancer-related instead of all palliative care studies. We also only examined studies published in the first six months of 2004 and 2009. This sample may not be representative of the greater supportive and palliative oncology literature, and may not have captured all the definitions related to each term. A systematic review looking for attempts to define each of the terms would be helpful. Second, the five-year interval may not be long enough to notice any change in frequency. Third, to ensure a high specificity of our review, we did not include some terms with similar meanings in our search strings, such as “palliative cancer care” and “hospice programs.” Finally, our search only examined definitions within the text and not cited references.

In summary, we documented the lack of definitions for commonly used terms in palliative care through a detailed review of the published literature. Our study highlighted the urgent need to derive consensual definitions. Until then, it is prudent to provide a definition or citation when using one of these terms.