Palliative Care Journal Club Issue #2

Head B, Ritchie CS and Smoot TM.   Prognostication in hospice care: can the palliative performance scale help?   J Pall Med 2005; 8:492-502.

Predicting prognosis in cancer patients is a combination of art and science.   The best data to help clinicians predict cancer prognosis in the final six months of life comes from an assessment of functional status.   The two most commonly used scales to measure functional status are the Karnofsky Performance Scale (KPS) and the Eastern Cooperative Oncology Group (ECOG) score.   A KPS < 50 or an ECOG score > 3 predicts a median survival of less than 3 months, assuming the scores are declining and are not an assessment of underlying chronic disease factors unrelated to the cancer (e.g. stroke).  

An article in the June 2005 Journal of Palliative Medicine discusses the use of the Palliative Performance Scale (PPS), originally developed in Canada, as yet another tool to help predict survival in cancer patients (1).   The PPS is an 11 point scale (0%, 10%, 20%, etc.) that assess functional status similar to the KPS, but adds dimensions of oral intake and level of consciousness.   Prior work has demonstrated the PPS to be highly correlated with the KPS.   This study evaluated the ability of the PPS to predict length of survival or discharge in a population of home based hospice patients.   The results of the study were:

• The PPS predicted length of survival to death.
• Patterns of change in the PPS correlated to both survival (declining PPS) and the need for discharge from hospice (stable PPS).
• Nurses coding the PPS had difficulty distinguishing between many of the PPS levels.   For example, there was poor reliability in differentiating a patient at a level of 10% vs. 20% or 30 vs. 40%.

This study adds to the growing literature on the use of the PPS as a prognostic tool for patients near the end-of-life.   This tool probably works as well as the more familiar KPS in cancer, but there is insufficient data that it is a better tool, and problems remain regarding the reliability of using an 11 point scale—in other words, it is not clear that clinicians can reliably distinguish 11 different levels of functional status in dying patients.    If hospices decide to use the PPS as their functional assessment scale, they should develop a rigorous training program to ensure that all staff are using the scale in a similar fashion.

• Head B, Ritchie CS and Smoot TM.   Prognostication in hospice care: can the palliative performance scale help?   J Pall Med 2005; 8:492-502.

See also:   Harrold J, Rickerson E, Carroll JT, et al. Is the palliative performance scale a useful predictor of mortality in a heterogeneous hospice population?   J Pall Med 2005; 8:503-509.

David E. Weissman, MD
Editor, Palliative Care Journal Club
Palliative Care Center
Medical College of Wisconsin

www.mcw.edu/pallmed

BLOG: http://growthhouse.typepad.com/david_weissman/