The Karnofsky Performance Scale Index allows patients to be classified as to their functional impairment. This can be used to compare effectiveness of different therapies and to assess the prognosis in individual patients. The lower the Karnofsky score, the worse the survival for most serious illnesses.

KARNOFSKY PERFORMANCE STATUS SCALE DEFINITIONS RATING (%) CRITERIA

Able to carry on normal activity and to work; no special care needed.   100   Normal 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 and care for most personal needs; varying amount of assistance 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 of his 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 is indicated although death not imminent.
20 Very sick; hospital admission necessary; active supportive treatment necessary.
10 Moribund; fatal processes progressing rapidly.
0 Dead

References:
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