You know that pesky eligibility criteria in nearly all clinical trials that is easy to miss – performance status (PS)? Well, performance status tools have a very rich and impressive history.
The earliest PS measure was developed in 1948 by Drs. David Karnofsky, Walter Abelman, Lloyd Craver, and James Burchneal. Named the Karnofsky Performance Status (KPS), the primary purpose of the development of the scale was to allow physicians to evaluate a patient’s ability to survive chemotherapy for cancer in a more objective manner.
A little more than a decade later in 1960, Dr. Charles Zubrod, who initiated the first NCI cooperative group (“Acute Leukemia Group B”), published the Zubrod scale. This scale is the forerunner of the ECOG Performance Status, which was first published in 1982.Sometimes you may see studies us the term “Zubrod/ECOG” to describe performance status.
In addition to KPS and ECOG, there is a version for children < 16 years of age. Named after Dr. Shirley Lansky, the Lansky Play-Performance Scale is a modification of the KPS and offers an approachable method for describing functional status in children. It was derived and internally validated in children with cancer to assess response to therapies and overall status.
Finally, if you have worked in hospice and palliative care, you are familiar with the Palliative Performance Scale (PPS). The PPS, which was originally developed in Canada in 1996, is a modification of the KPS and is designed specifically for measurement of physical status in palliative and hospice care settings. It is a validated and reliable tool used to assess a patient’s functional performance and to determine progression toward end of life. PPS measures include ambulation, self-care, intake, level of consciousness, activity, and evidence of disease.
Even though each of these scales have objective criteria for the numerical assignments, there is certainly a degree of subjectivity on the part of the clinician performing the assessment. As performance status is a measure of how well a person is able to carry on ordinary daily activities, it also provides an estimate of what treatments a person may tolerate.
- Karnofsky D, Burchenal J, The clinical evaluation of chemotherapeutic agents in cancer. In: MacLeod C, ed. Evaluation of Chemotherapeutic Agents. New York, NY: Columbia University Press; 1949:191–205.
- Zubrod C, Schneiderman MA, Frei E, et al. Appraisal of methods for the study of chemotherapy in man: Comparative therapeutic trial of nitrogen mustard and thiophosphoramide. Journal of Chronic Diseases; 1960:11:7-33.
- Lansky DA, List MA, Lansky LL, et al (1987). The measurement of performance in childhood cancer patients. Cancer 60 (7): 1651–6.
- Anderson F, Downing GM, Hill J. Palliative Performance Scale (PPS):a new tool. J Palliat Care. 1996; 12(1): 5-11
- Palliative Performance Scale (PPSv2) version 2. Medical Care of the Dying, 4th ed.; p. 121. ©Victoria Hospice Society, 2006