Support Care Cancer (2015) 23:913–918 DOI 10.1007/s00520-014-2440-8
ORIGINAL ARTICLE
Palliative performance scale and survival among outpatients with advanced cancer Jeff Myers & Audrey Kim & Jamie Flanagan & Debbie Selby
Received: 3 July 2014 / Accepted: 9 September 2014 / Published online: 18 September 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Previous studies have examined the association between the Palliative Performance Scale (PPS) and survival duration; however, few have examined patients with incurable cancer in the outpatient setting. In addition to exploring this association further, the purpose of this study was to identify key PPS markers that could serve as triggers to signify the need for key care discussions. Methods Study subjects were followed prospectively from the time of referral for a specialist palliative care consultation until death. PPS ratings and survival estimates were determined for each visit. Results For the final study population of 368 patients, at baseline, the median PPS rating was 60. Overall median and mean survival duration were approximately 4 and 6 months, respectively. Median survival duration for patients with PPS ratings of 70, 60, and 50 were found to be approximately 6, 3, and 2 months, respectively. Twenty-four percent of all survival estimates were found to be accurate. Conclusions Given the ongoing challenge of inaccurate survival estimates, this data suggests what may be of greatest clinical utility is to use specific PPS ratings as triggers for key care discussions among patients with incurable and progressive cancer.
J. Myers (*) Division of Palliative Care, Department of Family and Community Medicine, University of Toronto, Palliative Care Consult Team, Sunnybrook Health Sciences Centre, Rm H336, 2075 Bayview Avenue, Toronto, Ontario M4N 3 M5, Canada e-mail: [email protected] A. Kim : J. Flanagan : D. Selby Palliative Care Consult Team, Sunnybrook Health Sciences Centre, Rm H336, 2075, Bayview Avenue, Toronto, Ontario M4N 3 M5, Canada
Keywords Performance status . Survival duration . Survival estimation . Palliative care . Advanced cancer . Advance care planning
Introduction Physicians caring for patients with incurable illnesses are often asked to estimate likely survival duration for individual patients. Previous studies have established that physicians are notoriously inaccurate when estimating survival, with a consistent tendency to overestimate (i.e., patients live a shorter duration than expected) [1–3]. Factors that have been shown to have an impact on accuracy include clinician length of experience and strength of clinician-patient relationship [1]. Inaccurate survival estimates can have important implications for care, as both patient and physician may then approach decision-making and treatment recommendations, respectively, with a longer anticipated life span than what will actually occur. Within the setting of advanced or incurable cancer, a person’s understanding of their illness and their expectations for the future have been shown to substantially impact both the care decisions made and the overall patient outcome [4, 5]. Further, an overly optimistic survival estimate may lead to delays in key care discussions that address illness understanding and goals of care. Performance status has consistently been shown to strongly predict survival duration [6–8]. The Palliative Performance Scale (PPS) was designed to represent functional or performance status among patients receiving palliative care [9]. The PPS is comprised of 11 performance categories delineated in 10 % increments ranging from 0 (deceased) to 100 % (no evidence of disease, no limitations on any aspect of daily life) [9]. The categories are based on four domains including ambulation, activity level, evidence of disease, and self-care abilities/needs. A number of studies have reported a strongly
914
positive relationship between PPS and survival duration [10, 11]. However, the majority of these studies have been limited to study populations in home and/or inpatient palliative care settings (acute care wards or palliative care units) where the baseline PPS values are predominately under 60 % [12–14]. The PPS was developed before the field of palliative care had established a widespread presence in the outpatient setting, and since that time, there has been a rapid increase in the number of outpatient palliative care clinics, particularly for the setting of cancer care. The aim of the current study was to examine the association between PPS and survival among patients with incurable cancer in the outpatient setting. The specific objective was to identify key PPS markers that, by association with actual survival duration, could signify a need to ensure illness understanding and goals of care discussions are initiated.
Methods This prospective cohort study involved patients and clinicians from the outpatient Palliative Care Clinic within the Odette Cancer Centre at Sunnybrook Health Sciences Centre (SHSC), a comprehensive regional cancer centre within an academic tertiary care setting in Toronto, Canada. Eligible patients included any patient aged 18 or older with incurable cancer referred for outpatient specialty palliative care consultation. Over the 24-month study period, physicians wellexperienced with the PPS were asked to determine the PPS rating and indicate a survival estimate for enrolled patients at 1, 3, 6, 9, and 12 months post initial consult. Seven time-based categories (i.e., 0–7 days, 1–4 weeks, 1–3 months, 3– 6 months, 6–12 months, and >12 months) were used for survival estimates based on prior work [1]. A survival estimate was categorized as being accurate, an overestimate (actual survival duration was less than what was estimated), or an underestimate (actual survival duration was more than what was estimated). Accuracy was determined by comparing the actual survival duration with the survival estimate for each visit. Patient demographics including age, gender, and primary cancer diagnosis were collected. Total survival duration was calculated as the time between date of initial visit and date of death.
Support Care Cancer (2015) 23:913–918
population of 368 patients. Demographic data including age, gender, and primary cancer are outlined in Table 1. Among the total study population, the median PPS at baseline was 60 with a range of 20–90. Median and mean survival duration was approximately 4 and 6 months, respectively. PPS and survival estimate were each recorded for a total of 744 visits among the study population (Table 2). Among all survival estimates, only 24 % were found to be accurate with a marked tendency to overestimate survival across all PPS ratings. Given the level of inaccuracy among survival estimates, the relationship between performance status and survival estimates was further explored in a post hoc analysis using simulated PPS-based survival estimates. Individuals with a PPS of 60 or lower were automatically assigned a simulated survival estimate of 3 months. The cutoff of 3 months was chosen as among study patients with a PPS rating of 60; median survival duration was found to be approximately 3 months. To compare this with our actual study data, original survival estimates were first recategorized into binary estimates of 3 months (including all original estimates of 3–6, 6–12, and >12 months). Using these combined categories, the original physician estimates were found to be accurate for 53 % of the study population (n=195). In other words, the chance that an experienced palliative care physician accurately estimated survival duration to be either >3 or
ORIGINAL ARTICLE
Palliative performance scale and survival among outpatients with advanced cancer Jeff Myers & Audrey Kim & Jamie Flanagan & Debbie Selby
Received: 3 July 2014 / Accepted: 9 September 2014 / Published online: 18 September 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Previous studies have examined the association between the Palliative Performance Scale (PPS) and survival duration; however, few have examined patients with incurable cancer in the outpatient setting. In addition to exploring this association further, the purpose of this study was to identify key PPS markers that could serve as triggers to signify the need for key care discussions. Methods Study subjects were followed prospectively from the time of referral for a specialist palliative care consultation until death. PPS ratings and survival estimates were determined for each visit. Results For the final study population of 368 patients, at baseline, the median PPS rating was 60. Overall median and mean survival duration were approximately 4 and 6 months, respectively. Median survival duration for patients with PPS ratings of 70, 60, and 50 were found to be approximately 6, 3, and 2 months, respectively. Twenty-four percent of all survival estimates were found to be accurate. Conclusions Given the ongoing challenge of inaccurate survival estimates, this data suggests what may be of greatest clinical utility is to use specific PPS ratings as triggers for key care discussions among patients with incurable and progressive cancer.
J. Myers (*) Division of Palliative Care, Department of Family and Community Medicine, University of Toronto, Palliative Care Consult Team, Sunnybrook Health Sciences Centre, Rm H336, 2075 Bayview Avenue, Toronto, Ontario M4N 3 M5, Canada e-mail: [email protected] A. Kim : J. Flanagan : D. Selby Palliative Care Consult Team, Sunnybrook Health Sciences Centre, Rm H336, 2075, Bayview Avenue, Toronto, Ontario M4N 3 M5, Canada
Keywords Performance status . Survival duration . Survival estimation . Palliative care . Advanced cancer . Advance care planning
Introduction Physicians caring for patients with incurable illnesses are often asked to estimate likely survival duration for individual patients. Previous studies have established that physicians are notoriously inaccurate when estimating survival, with a consistent tendency to overestimate (i.e., patients live a shorter duration than expected) [1–3]. Factors that have been shown to have an impact on accuracy include clinician length of experience and strength of clinician-patient relationship [1]. Inaccurate survival estimates can have important implications for care, as both patient and physician may then approach decision-making and treatment recommendations, respectively, with a longer anticipated life span than what will actually occur. Within the setting of advanced or incurable cancer, a person’s understanding of their illness and their expectations for the future have been shown to substantially impact both the care decisions made and the overall patient outcome [4, 5]. Further, an overly optimistic survival estimate may lead to delays in key care discussions that address illness understanding and goals of care. Performance status has consistently been shown to strongly predict survival duration [6–8]. The Palliative Performance Scale (PPS) was designed to represent functional or performance status among patients receiving palliative care [9]. The PPS is comprised of 11 performance categories delineated in 10 % increments ranging from 0 (deceased) to 100 % (no evidence of disease, no limitations on any aspect of daily life) [9]. The categories are based on four domains including ambulation, activity level, evidence of disease, and self-care abilities/needs. A number of studies have reported a strongly
914
positive relationship between PPS and survival duration [10, 11]. However, the majority of these studies have been limited to study populations in home and/or inpatient palliative care settings (acute care wards or palliative care units) where the baseline PPS values are predominately under 60 % [12–14]. The PPS was developed before the field of palliative care had established a widespread presence in the outpatient setting, and since that time, there has been a rapid increase in the number of outpatient palliative care clinics, particularly for the setting of cancer care. The aim of the current study was to examine the association between PPS and survival among patients with incurable cancer in the outpatient setting. The specific objective was to identify key PPS markers that, by association with actual survival duration, could signify a need to ensure illness understanding and goals of care discussions are initiated.
Methods This prospective cohort study involved patients and clinicians from the outpatient Palliative Care Clinic within the Odette Cancer Centre at Sunnybrook Health Sciences Centre (SHSC), a comprehensive regional cancer centre within an academic tertiary care setting in Toronto, Canada. Eligible patients included any patient aged 18 or older with incurable cancer referred for outpatient specialty palliative care consultation. Over the 24-month study period, physicians wellexperienced with the PPS were asked to determine the PPS rating and indicate a survival estimate for enrolled patients at 1, 3, 6, 9, and 12 months post initial consult. Seven time-based categories (i.e., 0–7 days, 1–4 weeks, 1–3 months, 3– 6 months, 6–12 months, and >12 months) were used for survival estimates based on prior work [1]. A survival estimate was categorized as being accurate, an overestimate (actual survival duration was less than what was estimated), or an underestimate (actual survival duration was more than what was estimated). Accuracy was determined by comparing the actual survival duration with the survival estimate for each visit. Patient demographics including age, gender, and primary cancer diagnosis were collected. Total survival duration was calculated as the time between date of initial visit and date of death.
Support Care Cancer (2015) 23:913–918
population of 368 patients. Demographic data including age, gender, and primary cancer are outlined in Table 1. Among the total study population, the median PPS at baseline was 60 with a range of 20–90. Median and mean survival duration was approximately 4 and 6 months, respectively. PPS and survival estimate were each recorded for a total of 744 visits among the study population (Table 2). Among all survival estimates, only 24 % were found to be accurate with a marked tendency to overestimate survival across all PPS ratings. Given the level of inaccuracy among survival estimates, the relationship between performance status and survival estimates was further explored in a post hoc analysis using simulated PPS-based survival estimates. Individuals with a PPS of 60 or lower were automatically assigned a simulated survival estimate of 3 months. The cutoff of 3 months was chosen as among study patients with a PPS rating of 60; median survival duration was found to be approximately 3 months. To compare this with our actual study data, original survival estimates were first recategorized into binary estimates of 3 months (including all original estimates of 3–6, 6–12, and >12 months). Using these combined categories, the original physician estimates were found to be accurate for 53 % of the study population (n=195). In other words, the chance that an experienced palliative care physician accurately estimated survival duration to be either >3 or
