The Karnofsky Performance Scale (KPS) is an assessment tool for predicting the  length of survival in terminally ill patients. The KPS is an 11 point rating scale which  ranges from normal functioning (100) to dead (0) in ten point increments.​ ​Use of  these 11 points is necessary, meaning that estimates between points cannot be  made.

Although no specific instructions were originally developed for administration of  the KPS, guidelines have recently been developed to assist in improving consistency  and reliability of the scale. Research has suggested that seven variables account for  a significant amount of variance in scoring of the KPS and represented all four  categories of the KPS — evidence of disease, daily activity, self care and work.

Karnofsky Performance Status Scale - KPS scale
Karnofsky et al. Cancer. 1948;1(4):634-56