Karnofsky Performance Score

The Karnofsky Performance Scale (KPS) is one of the oldest and most extensively validated clinical tools for measuring a cancer patient's functional status and ability to perform daily activities. Developed by David Karnofsky and Joseph Burchenal and published in 1949, it was originally designed to evaluate the effects of chemotherapy on patients' capacity to care for themselves and perform normal activity. The scale runs from 0 (dead) to 100 (normal, no evidence of disease) in 10-point increments, with each level defined by a descriptive statement of functional capacity. KPS 100 indicates a completely normal person with no complaints and no evidence of disease. KPS 90 describes a person who is able to carry on normal activity but has minor signs or symptoms of disease. KPS 80 allows normal activity with effort and some signs of disease. KPS 70 describes a person who is able to care for themselves but unable to carry on normal activity or active work. KPS 60 requires occasional assistance from others but is mostly capable of self-care. KPS 50 requires considerable assistance and frequent medical care. KPS 40 describes a disabled person who requires special care and assistance. KPS 30 is severely disabled, hospitalisation indicated. KPS 20 is very sick, requiring active supportive treatment and hospitalisation. KPS 10 describes a moribund person with rapidly progressive fatal disease, and KPS 0 is death. The KPS is more granular than the ECOG Performance Status (6 levels vs 11) and is particularly useful in palliative care for documenting nuanced functional changes over time. A KPS of 50 or below is often used as a threshold for consideration of hospice referral, and KPS below 40 is associated with very limited life expectancy.

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1. 1Begin with the highest tier (100) and work downward by asking whether the patient has any limitations. Can the patient carry on normal activity and work? Are there any symptoms or signs of disease?
2. 2Assess independence vs. need for assistance: determine whether the patient can care for themselves without help (KPS 70–100), needs occasional assistance (KPS 50–60), or requires substantial or continuous assistance (KPS 10–40).
3. 3Determine whether the patient is able to remain at home or requires hospitalisation or institutional care. Those who require frequent hospitalisation or institutional support score KPS 40 or below.
4. 4Assess disease activity: is the patient experiencing active, progressive, or symptomatic disease? Grade the severity of symptoms on daily function — minor symptoms allow KPS 90, more significant symptoms or requirement for effort reduce the score further.
5. 5Consider specific descriptors for each 10-point level: KPS 80 means activities are possible but require effort; KPS 70 means self-care is maintained but work is not possible; KPS 60 means occasional help is needed but most care is self-directed.
6. 6Cross-reference with ECOG if needed: KPS ÷ 10 − 10 provides an approximate ECOG equivalent (e.g., KPS 70 ≈ ECOG 1–2).
7. 7Document the KPS score at each visit with the date and clinical rationale, enabling reliable tracking of functional trajectory over the disease course and treatment period.

• !Rounding to the nearest convenient score without using the specific descriptors — KPS should be assigned based on the defined descriptors at each 10-point level, not estimated as a percentage of normal.
• !Treating KPS as equivalent to ECOG for trial eligibility purposes without converting — some trials state 'ECOG 0–1' which is approximately KPS 70–100, not KPS 60 or below.
• !Failing to document KPS at every visit — without serial documentation, deteriorating functional status may not be detected until the patient presents critically unwell.
• !Using KPS to guide chemotherapy dosing in the same way as ECOG — the two scales are close but not identical, and dosing algorithms should specify which scale they are based on.
• !Not distinguishing reversible from irreversible functional decline when assigning KPS — a patient who is KPS 40 from uncontrolled pain may return to KPS 70 with adequate analgesia.
• !Applying KPS criteria designed for adults directly to children without using the age-appropriate Lansky scale, which uses play activity rather than work as the functional reference.