Karnofsky Performance Scale (KPS) — Functional Status Assessment
The Karnofsky Performance Scale (KPS) is a widely used 11-point scale (0-100) that quantifies a patient's functional status and ability to perform activities of daily living. It is commonly used in oncology, palliative care, and geriatrics.
About
The Karnofsky Performance Scale was developed by Dr. David A. Karnofsky and colleagues in 1948 as a standard tool for assessing the functional status of patients receiving chemotherapy. It was one of the first systematic attempts to quantify the impact of disease and treatment on a patient's daily functioning. The scale ranges from 100 (normal, no complaints) to 0 (dead) in 10-point decrements, with descriptive anchors at each level. KPS has been validated across multiple clinical settings including oncology, geriatrics, palliative care, and rehabilitation medicine. The scale correlates with prognosis across various diseases: each 10-point decrease in KPS is associated with a corresponding increase in mortality risk. In lung cancer, for example, patients with KPS ≥80 have a 40% better 1-year survival compared to those with KPS ≤70. KPS is used to: (1) determine eligibility for chemotherapy and clinical trials, (2) guide treatment intensity, (3) predict treatment tolerance and toxicity, (4) estimate prognosis and survival, (5) identify patients who may benefit from palliative care, (6) assess the need for nursing home placement or home health services. Alternative performance status measures include the ECOG Performance Status (0-5), which is simpler but less granular. The two scales correlate well: KPS 100 = ECOG 0, KPS 80-90 = ECOG 1, KPS 60-70 = ECOG 2, KPS 40-50 = ECOG 3, KPS 10-30 = ECOG 4, KPS 0 = ECOG 5. KPS continues to be the standard functional assessment tool in palliative care research and is a required data element in many cancer registries and clinical trials.
Formula
Select the score (0-100 in 10-point increments) that best describes the patient's current functional status.
The KPS is a clinician-rated scale that assesses the patient's current functional status. The scale uses 10-point decrements from 100 (normal function) to 0 (dead). The clinician selects the closest descriptor. Higher scores indicate better function. For oncology patients, KPS ≥80 generally indicates ability to tolerate standard chemotherapy; KPS 50-70 suggests need for treatment modification; KPS ≤40 suggests palliative care focus. Conversion to ECOG: KPS 100 = ECOG 0, KPS 80-90 = ECOG 1, KPS 60-70 = ECOG 2, KPS 40-50 = ECOG 3, KPS 10-30 = ECOG 4, KPS 0 = ECOG 5.
Score Interpretation
The Karnofsky Performance Scale is the most established functional assessment tool in oncology and palliative care. It has been validated in over 1,000 studies across multiple cancer types and care settings. KPS is a strong independent predictor of survival: patients with KPS ≥80 have median survival 2-3 times longer than those with KPS ≤70 across multiple cancer types. In palliative care, KPS is used to estimate prognosis, with KPS ≤50 associated with a median survival of less than 3 months. The scale is also used in geriatric assessment, rehabilitation medicine, and HIV care. The main limitation of KPS compared to ECOG PS is its greater complexity (11 vs 6 categories) and the perception of false precision in the 10-point increments. However, KPS provides more granularity for detecting small changes in functional status.
Able to carry on normal activity — 80–100
KPS 80-100. Able to carry on normal activity and work. No special care needed.
Management: Fully functional. Can tolerate standard treatment regimens. Routine monitoring.
Unable to work, able to live at home — 50–70
KPS 50-70. Unable to work but can live at home. Requires varying degrees of assistance.
Management: May require treatment modification. Assess support services. Monitor for decline.
Unable to care for self — 10–40
KPS 10-40. Disabled to very sick. Requires institutional or hospital care.
Management: Consider palliative approach. Discuss goals of care. Focus on symptom management.
Dead — 0–0
KPS 0. Dead.
Management: End-of-life care documentation.
Reference Ranges
| Population | Normal Range | Notes |
|---|---|---|
| Adults with cancer | 100-80 (Normal activity) to 0 (Dead) | ≥80 = standard chemo candidate, 50-70 = modified treatment, ≤40 = palliative focus |
Dr. Khaled Hassan
Dr. Khaled is a cardiology consultant with experience in acute cardiac care.
View medical review board & editorial policy →Example Calculation
A 55-year-old man with metastatic pancreatic cancer presents for follow-up. He reports that he is able to perform all self-care activities independently (bathing, dressing, eating) but cannot work and requires assistance with shopping and heavy housework. He spends approximately 60% of his waking hours out of bed. KPS: 70 — Cares for self, unable to carry on normal activity or active work. This corresponds to ECOG PS 2. Treatment modification and assessment of home support services are recommended.
Related Conditions
Common Mistakes
Using KPS and ECOG PS interchangeably without proper conversion
KPS and ECOG PS are different scales with different granularity. When converting: KPS 100 = ECOG 0, KPS 80-90 = ECOG 1, KPS 60-70 = ECOG 2, KPS 40-50 = ECOG 3, KPS 10-30 = ECOG 4, KPS 0 = ECOG 5. Never use them interchangeably without acknowledging the conversion.
Assigning KPS based on treatment intent rather than actual function
KPS should reflect the patient's actual current functional status, not the clinician's treatment plan. A patient receiving palliative chemotherapy can have KPS 80 if they are functioning well, while a patient receiving curative therapy may have KPS 50 due to treatment side effects. The KPS score describes function, not treatment intent.
Frequently Asked Questions
How does KPS compare to ECOG PS in clinical use?
What is the prognostic value of KPS in palliative care?
References
- Karnofsky DA, Abelmann WH, Craver LF, et al. The use of the nitrogen mustards in the palliative treatment of carcinoma. Cancer. 1948;1(4):634-656.
- Schag CC, Heinrich RL, Ganz PA. Karnofsky performance status revisited: reliability, validity, and guidelines. J Clin Oncol. 1984;2(3):187-193. PubMed
- Mor V, Laliberte L, Morris JN, et al. The Karnofsky Performance Status Scale: an examination of its reliability and validity in a research setting. Cancer. 1984;53(9):2002-2007. PubMed