Karnofsky Performance Status Scale

The Karnofsky Performance Scale Index is an assessment tool for functional impairment, it is a measure of the patient’s overall performance status or ability to perform their activities of daily living ¹. Karnofsky scale can be used to compare effectiveness of different therapies and to assess the prognosis in individual patients. In most serious illnesses, the lower the Karnofsky score, the worse the likelihood of survival. Karnofsky Performance Scale is a single score between 10 and 100 assigned by a clinician based on observations of a patient’s ability to perform common tasks relating to activity, work and self-care. A score of 100 signifies normal physical abilities with no evidence of disease. Decreasing numbers indicate a reduced performance status.

David Karnofsky and Joseph Burchenal in the late 1940s devised the numerical scale termed the ‘performance status’ of cancer patients, for a trial of nitrogen mustard in the treatment of lung cancer patients ². The Karnofsky scale covered 11 stages from 100 (normal health) to 0 (death).

Table 1. Karnofsky Performance Status Scale

Condition	Value (%)	Level of Functional Capacity
Able to carry on normal activity and to work. No special care is needed.	100%	No complaints; no evidence of disease
	90%	Able to carry on normal activity; minor signs or symptoms of disease
	80%	Normal activity with effort; some signs or symptoms of disease
Unable to work. Able to live at home, care for most personal needs. A varying amount of assistance is needed.	70%	Cares for self; unable to carry on normal activity or to do active work
	60%	Requires occasional assistance but is able to care for most personal needs
	50%	Requires considerable assistance and frequent medical care
Unable to care for self. Requires equivalent of institutional or hospital care. Disease may be progressing rapidly.	40%	Disabled; requires special care and assistance
	30%	Severely disabled; hospital admission indicated although death not imminent
	20%	Very sick; hospital admission necessary; active supportive treatment necessary
	10%	Moribund; fatal processes progressing rapidly
	0%	Dead

[Source ³ ] References

1. de Haan R, Aaronson N, Limburg M, Hewer RL, van Crevel H. Measuring quality of life in stroke. Stroke. 1993 Feb. 24(2):320-7.
2. Karnofsky DA, Burchenal JH. The clinical evaluation of chemotherapeutic agents in cancer. In: MacLeod CM, editor. (eds). Evaluation of chemotherapeutic agents, New York: Columbia University Press, 1949, pp. 191–205
3. Karnofsky DA, Abelmann WH, Craver LF, et al. The use of the nitrogen mustards in the palliative treatment of carcinoma. With particular reference to bronchogenic carcinoma. Cancer 1948; 1(4): 634–656.