JOURNAL OF PALLIATIVE MEDICINE Volume 17, Number 3, 2014 ª Mary Ann Liebert, Inc. DOI: 10.1089/jpm.2013.0603
Does the Palliative Performance Scale Have Added Value Over the Karnofsky Performance Status in Ambulatory Cancer Patients Receiving Palliative Care? Carlos Eduardo Paiva, MD, PhD1–3 and Bianca Sakamoto Ribeiro Paiva, RN, PhD2,3
Dear Editor: Since 1948 the Karnofsky Performance Status (KPS) scale has been widely utilized as an assessment tool to define performance status (PS) in oncology.1 It has certain limitations that have motivated adaptations over time. In particular, the focus of the KPS on the need for hospitalization and medical intervention challenges the evaluation of advanced cancer patients that are being treated according to the palliative care (PC) philosophy.2 The Palliative Performance Scale (PPS), which was developed
in 1996, was adapted from the KPS as a novel tool to quantify the PS of patients receiving PC.3 The utility of the PPS outside the context of end-of-life care requires further clarification. Seow and colleagues4 analyzed the PPS scores from a large cohort of ambulatory cancer patients (n = 11,342); in this cohort, 78.5% of the patients presented with an initial PPS higher than 60%. The relative hazard of death increased by a factor of 1.69 for each 10-point decrease in the PPS score. We believe that this study is relevant because it provided new
Table 1. Multivariate Survival Analysis of Ambulatory Advanced Cancer Patients According to the Karnofsky Performance Status and Palliative Performance Scale Model 1a HR
95% CI
KPS 0.963 0.941–0.984 PPS 1.003 0.980–1.026 Age 0.988 0.974–1.002 Antineoplastic active treatment Yes 1 – No 1.414 1.002–1.996 Primary tumor Lung 1 – Breast 0.618 0.333–1.147 Gynecological 0.994 0.507–1.949 UGI 1.176 0.653–2.118 LGI 1.365 0.727–2.561 Urological 0.861 0.468–1.587 Hematological 0.446 0.100–1.995 SST 1.251 0.545–2.872 Head and neck 0.943 0.448–1.985 Unknown 0.886 0.301–2.608 Number of metastatic sites 0 1 – 1 1.534 0.980–2.402 2 2.151 1.301–3.555 ‡3 2.517 1.341–4.724
Model 2
Model 3
p
HR
95% CI
p
HR
95% CI
p
0.001 0.810 0.105
– 0.971 0.991
– 0.959–0.983 0.977–1.005
– < 0.001 0.196
0.965 – 0.988
0.953–0.977 – 0.974–1.002
< 0.001 – 0.101
0.049
1 1.455
– 1.031–2.053
0.033
1 1.412
– 1.001–1.993
0.049
0.492 0.127 0.987 0.590 0.333 0.632 0.291 0.597 0.878 0.826
1 0.561 0.907 1.183 1.449 0.958 0.437 1.303 0.851 0.886
– 0.301–1.043 0.462–1.779 0.657–2.131 0.770–2.726 0.522–1.758 0.098–1.943 0.568–2.898 0.406–1.781 0.302–1.600
0.271 0.068 0.776 0.576 0.250 0.889 0.277 0.532 0.668 0.826
1 0.616 0.996 1.180 1.382 0.871 0.443 1.260 0.939 0.893
– 0.332–1.142 0.508–1.952 0.655–2.123 0.742–2.572 0.476–1.593 0.099–1.979 0.550–2.887 0.447–1.974 0.304–2.887
0.451 0.124 0.990 0.582 0.308 0.653 0.286 0.585 0.868 0.836
0.006 0.061 0.003 0.004
1 1.650 2.020 2.927
– 1.057–2.578 1.228–3.323 1.568–5.463
0.003 0.028 0.006 0.001
1 1.539 2.147 2.522
– 0.984–2.407 1.300–3.548 1.344–4.732
0.006 0.059 0.003 0.004
a Model 1 includes both the KPS and the PPS, model 2 only includes the PPS, and model 3 only includes the KPS. KPS, Karnofsky Performance Status; LGI, low gastrointestinal; PPS, Palliative Performance Scale; SST, skin and soft tissue; UGI, upper gastrointestinal.
1 2 3
Department of Clinical Oncology, Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil. Learning and Research Institute, Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil. Quality of Life Research Group (GPQual), Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil.
264
LETTERS TO THE EDITOR
robust data regarding the utility of the PPS in determining the prognosis of ambulatory advanced cancer patients (ACPs), outside the context of end-of-life care. The PPS and the KPS were prospectively calculated in 220 ACPs during their first consult in our PC outpatient clinic. Additionally, the patients answered the European Organization for Research and Treatment of Cancer Care Quality of Life Questionnaire (EORTC QLQ-C30) to enable the correlation between the PS scores and the physical functioning subscale. All the patients were followed until death or the time of analysis (planned for after 70% of the deaths had occurred). Univariate and multivariate analyses were performed using the Cox proportional hazards model. The mean (standard deviation) values of the KPS and PPS were 75.5 (15.1) and 75.8 (14.5), respectively. There were 112 (50.7%) men, with a mean age of 60 years, and 116 (52.5%) patients were undergoing palliative chemotherapy. We observed a KPS/PPS concordance rate of 56.3%; when accepting an error of – 10%, the concordance rate rose to 97.3%. The Spearman correlation coefficient between the KPS and the PPS was 0.876 ( p < 0.001). As expected, there were similarly strong correlations between physical functioning and the KPS (0.537, p < 0.001) and the PPS (0.557, p < 0.001). The univariate analysis of survival revealed a prognostic impact for both the KPS (HR: 0.968, 95% CI 0.957–0.978, p < 0.001) and the PPS (HR: 0.974, 95% CI 0.964–0.985, p < 0.001). When the KPS and the PPS were analyzed separately using multivariate Cox regression analysis, they both remained independent prognostic factors (models A and B, respectively; see Table 1). When both scores were included in the analysis, only the KPS remained in the final prognostic model (model C; see Table 1).
265
We agree with Seow and colleagues4 that the PPS is a valid tool in ambulatory settings that provides valuable prognostic information. However, at least in outpatients with good clinical performance, the PPS has no added value over the KPS. Considering the simultaneous model of care, where patients are referred sooner to PC, these results may influence the logistics of certain cancer outpatient clinics. References
1. Karnofsky DA, Abelmann WH, Craver LF, Burchenal JH: The use of nitrogen mustard in the palliative treament of cancer. Cancer 1948:22. 2. Abernethy AP, Shelby-James T, Fazekas BS, Woods D, Currow DC: The Australia-modified Karnofsky Performance Status (AKPS) scale: A revised scale for contemporary palliative care clinical practice [ISRCTN81117481]. BMC Palliat Care 2005;4:7. 3. Anderson F, Downing GM, Hill J, Casorso L, Lerch N: Palliative performance scale (PPS): A new tool. J Palliat Care 1996;12:5–11. 4. Seow H, Barbera L, Dudgeon D, Howell D, Husain A, Atzema C, et al.: The association of the palliative performance scale and hazard of death in an ambulatory cancer population. J Palliat Med 2013;16:156–162.
Address correspondence to: Carlos Eduardo Paiva, MD, PhD Departamento de Oncologia Clı´nica Rua Antenor Duarte Villela 1331- Barretos Sa˜o Paulo, Brazil E-mail: [email protected]
Does the Palliative Performance Scale Have Added Value Over the Karnofsky Performance Status in Ambulatory Cancer Patients Receiving Palliative Care? Carlos Eduardo Paiva, MD, PhD1–3 and Bianca Sakamoto Ribeiro Paiva, RN, PhD2,3
Dear Editor: Since 1948 the Karnofsky Performance Status (KPS) scale has been widely utilized as an assessment tool to define performance status (PS) in oncology.1 It has certain limitations that have motivated adaptations over time. In particular, the focus of the KPS on the need for hospitalization and medical intervention challenges the evaluation of advanced cancer patients that are being treated according to the palliative care (PC) philosophy.2 The Palliative Performance Scale (PPS), which was developed
in 1996, was adapted from the KPS as a novel tool to quantify the PS of patients receiving PC.3 The utility of the PPS outside the context of end-of-life care requires further clarification. Seow and colleagues4 analyzed the PPS scores from a large cohort of ambulatory cancer patients (n = 11,342); in this cohort, 78.5% of the patients presented with an initial PPS higher than 60%. The relative hazard of death increased by a factor of 1.69 for each 10-point decrease in the PPS score. We believe that this study is relevant because it provided new
Table 1. Multivariate Survival Analysis of Ambulatory Advanced Cancer Patients According to the Karnofsky Performance Status and Palliative Performance Scale Model 1a HR
95% CI
KPS 0.963 0.941–0.984 PPS 1.003 0.980–1.026 Age 0.988 0.974–1.002 Antineoplastic active treatment Yes 1 – No 1.414 1.002–1.996 Primary tumor Lung 1 – Breast 0.618 0.333–1.147 Gynecological 0.994 0.507–1.949 UGI 1.176 0.653–2.118 LGI 1.365 0.727–2.561 Urological 0.861 0.468–1.587 Hematological 0.446 0.100–1.995 SST 1.251 0.545–2.872 Head and neck 0.943 0.448–1.985 Unknown 0.886 0.301–2.608 Number of metastatic sites 0 1 – 1 1.534 0.980–2.402 2 2.151 1.301–3.555 ‡3 2.517 1.341–4.724
Model 2
Model 3
p
HR
95% CI
p
HR
95% CI
p
0.001 0.810 0.105
– 0.971 0.991
– 0.959–0.983 0.977–1.005
– < 0.001 0.196
0.965 – 0.988
0.953–0.977 – 0.974–1.002
< 0.001 – 0.101
0.049
1 1.455
– 1.031–2.053
0.033
1 1.412
– 1.001–1.993
0.049
0.492 0.127 0.987 0.590 0.333 0.632 0.291 0.597 0.878 0.826
1 0.561 0.907 1.183 1.449 0.958 0.437 1.303 0.851 0.886
– 0.301–1.043 0.462–1.779 0.657–2.131 0.770–2.726 0.522–1.758 0.098–1.943 0.568–2.898 0.406–1.781 0.302–1.600
0.271 0.068 0.776 0.576 0.250 0.889 0.277 0.532 0.668 0.826
1 0.616 0.996 1.180 1.382 0.871 0.443 1.260 0.939 0.893
– 0.332–1.142 0.508–1.952 0.655–2.123 0.742–2.572 0.476–1.593 0.099–1.979 0.550–2.887 0.447–1.974 0.304–2.887
0.451 0.124 0.990 0.582 0.308 0.653 0.286 0.585 0.868 0.836
0.006 0.061 0.003 0.004
1 1.650 2.020 2.927
– 1.057–2.578 1.228–3.323 1.568–5.463
0.003 0.028 0.006 0.001
1 1.539 2.147 2.522
– 0.984–2.407 1.300–3.548 1.344–4.732
0.006 0.059 0.003 0.004
a Model 1 includes both the KPS and the PPS, model 2 only includes the PPS, and model 3 only includes the KPS. KPS, Karnofsky Performance Status; LGI, low gastrointestinal; PPS, Palliative Performance Scale; SST, skin and soft tissue; UGI, upper gastrointestinal.
1 2 3
Department of Clinical Oncology, Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil. Learning and Research Institute, Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil. Quality of Life Research Group (GPQual), Barretos Cancer Hospital, Barretos, Sa˜o Paulo, Brazil.
264
LETTERS TO THE EDITOR
robust data regarding the utility of the PPS in determining the prognosis of ambulatory advanced cancer patients (ACPs), outside the context of end-of-life care. The PPS and the KPS were prospectively calculated in 220 ACPs during their first consult in our PC outpatient clinic. Additionally, the patients answered the European Organization for Research and Treatment of Cancer Care Quality of Life Questionnaire (EORTC QLQ-C30) to enable the correlation between the PS scores and the physical functioning subscale. All the patients were followed until death or the time of analysis (planned for after 70% of the deaths had occurred). Univariate and multivariate analyses were performed using the Cox proportional hazards model. The mean (standard deviation) values of the KPS and PPS were 75.5 (15.1) and 75.8 (14.5), respectively. There were 112 (50.7%) men, with a mean age of 60 years, and 116 (52.5%) patients were undergoing palliative chemotherapy. We observed a KPS/PPS concordance rate of 56.3%; when accepting an error of – 10%, the concordance rate rose to 97.3%. The Spearman correlation coefficient between the KPS and the PPS was 0.876 ( p < 0.001). As expected, there were similarly strong correlations between physical functioning and the KPS (0.537, p < 0.001) and the PPS (0.557, p < 0.001). The univariate analysis of survival revealed a prognostic impact for both the KPS (HR: 0.968, 95% CI 0.957–0.978, p < 0.001) and the PPS (HR: 0.974, 95% CI 0.964–0.985, p < 0.001). When the KPS and the PPS were analyzed separately using multivariate Cox regression analysis, they both remained independent prognostic factors (models A and B, respectively; see Table 1). When both scores were included in the analysis, only the KPS remained in the final prognostic model (model C; see Table 1).
265
We agree with Seow and colleagues4 that the PPS is a valid tool in ambulatory settings that provides valuable prognostic information. However, at least in outpatients with good clinical performance, the PPS has no added value over the KPS. Considering the simultaneous model of care, where patients are referred sooner to PC, these results may influence the logistics of certain cancer outpatient clinics. References
1. Karnofsky DA, Abelmann WH, Craver LF, Burchenal JH: The use of nitrogen mustard in the palliative treament of cancer. Cancer 1948:22. 2. Abernethy AP, Shelby-James T, Fazekas BS, Woods D, Currow DC: The Australia-modified Karnofsky Performance Status (AKPS) scale: A revised scale for contemporary palliative care clinical practice [ISRCTN81117481]. BMC Palliat Care 2005;4:7. 3. Anderson F, Downing GM, Hill J, Casorso L, Lerch N: Palliative performance scale (PPS): A new tool. J Palliat Care 1996;12:5–11. 4. Seow H, Barbera L, Dudgeon D, Howell D, Husain A, Atzema C, et al.: The association of the palliative performance scale and hazard of death in an ambulatory cancer population. J Palliat Med 2013;16:156–162.
Address correspondence to: Carlos Eduardo Paiva, MD, PhD Departamento de Oncologia Clı´nica Rua Antenor Duarte Villela 1331- Barretos Sa˜o Paulo, Brazil E-mail: [email protected]
