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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.
KPS 100 = Normal, no complaints; KPS 90 = Able to carry on normal activity, minor symptoms; KPS 80 = Normal activity with effort; KPS 70 = Cares for self, unable to work; KPS 60 = Requires occasional assistance; KPS 50 = Requires considerable assistance; KPS 40 = Disabled, requires special care; KPS 30 = Severely disabled, hospitalisation indicated; KPS 20 = Very sick, active support needed; KPS 10 = Moribund; KPS 0 = Dead
- 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?
- 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).
- 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.
- 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.
- 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.
- 6Cross-reference with ECOG if needed: KPS ÷ 10 − 10 provides an approximate ECOG equivalent (e.g., KPS 70 ≈ ECOG 1–2).
- 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.
Able to carry on normal activity — eligible for most cancer treatments and trials
KPS 90 patients have minimal functional impact from their disease. They typically tolerate full-dose systemic therapy well and are eligible for most clinical trial protocols.
Requires occasional assistance — consider dose-modified chemotherapy or oral targeted therapy
KPS 60 corresponds to approximately ECOG 2. The patient has significant functional limitation but can remain at home. Treatment options should balance efficacy with manageable toxicity.
Hospitalisation indicated; active systemic treatment not appropriate; palliative focus
KPS 30 corresponds to approximately ECOG 3–4. This patient requires intensive supportive care and goals-of-care discussion. Cytotoxic therapy carries unacceptable risk relative to benefit at this functional level.
Rapid decline to KPS 20 — median survival typically < 2–4 weeks; hospice referral recommended
KPS below 30 in the context of progressive malignancy is associated with very short life expectancy. This patient and their family should be offered urgent specialist palliative care and hospice referral.
Professionals in health and medical use Karnofsky Score as part of their standard analytical workflow to verify calculations, reduce arithmetic errors, and produce consistent results that can be documented, audited, and shared with colleagues, clients, or regulatory bodies for compliance purposes.
University professors and instructors incorporate Karnofsky Score into course materials, homework assignments, and exam preparation resources, allowing students to check manual calculations, build intuition about input-output relationships, and focus on conceptual understanding rather than arithmetic.
Consultants and advisors use Karnofsky Score to quickly model different scenarios during client meetings, enabling real-time exploration of what-if questions that would otherwise require returning to the office for detailed spreadsheet-based analysis and reporting.
Individual users rely on Karnofsky Score for personal planning decisions — comparing options, verifying quotes received from service providers, checking third-party calculations, and building confidence that the numbers behind an important decision have been computed correctly and consistently.
Extreme input values
In practice, this edge case requires careful consideration because standard assumptions may not hold. When encountering this scenario in karnofsky score calculations, practitioners should verify boundary conditions, check for division-by-zero risks, and consider whether the model's assumptions remain valid under these extreme conditions.
Assumption violations
In practice, this edge case requires careful consideration because standard assumptions may not hold. When encountering this scenario in karnofsky score calculations, practitioners should verify boundary conditions, check for division-by-zero risks, and consider whether the model's assumptions remain valid under these extreme conditions.
Rounding and precision effects
In practice, this edge case requires careful consideration because standard assumptions may not hold. When encountering this scenario in karnofsky score calculations, practitioners should verify boundary conditions, check for division-by-zero risks, and consider whether the model's assumptions remain valid under these extreme conditions.
| KPS Score | Description | ECOG Equivalent | Clinical Implication |
|---|---|---|---|
| 100 | Normal, no complaints, no disease evidence | 0 | All treatments/trials eligible |
| 90 | Normal activity, minor disease symptoms | 0 | All treatments/trials eligible |
| 80 | Normal activity with effort, some symptoms | 1 | Most treatments eligible |
| 70 | Cares for self, unable to work | 1 | Most treatments eligible |
| 60 | Requires occasional assistance, mostly self-care | 2 | Modified dose; limited trials |
| 50 | Requires considerable assistance and frequent care | 2 | Careful consideration of benefits/risks |
| 40 | Disabled, requires special care | 3 | Cytotoxics usually inappropriate |
| 30 | Severely disabled, hospitalisation indicated | 3 | Best supportive care |
| 20 | Very sick, hospitalised, active support needed | 4 | Hospice referral |
| 10 | Moribund, rapidly progressing fatal disease | 4 | Hospice and comfort measures only |
| 0 | Dead | 5 | — |
What is the Karnofsky Performance Scale?
Karnofsky Score is a specialized calculation tool designed to help users compute and analyze key metrics in the health and medical domain. It takes specific numeric inputs — typically drawn from real-world data such as measurements, rates, or quantities — and applies a validated mathematical formula to produce actionable results. The tool is valuable because it eliminates manual calculation errors, provides instant feedback when exploring different scenarios, and serves as both a decision-support instrument for professionals and a learning aid for students studying the underlying principles.
What KPS score indicates poor prognosis?
KPS below 50 is generally associated with significantly reduced life expectancy and poor tolerance of cytotoxic chemotherapy. KPS 30 or below is typically associated with median survival measured in weeks to a few months in the context of advanced malignancy. KPS below 40 is commonly used as a trigger for hospice referral consideration.
How does KPS relate to ECOG performance status?
ECOG 0 ≈ KPS 100; ECOG 1 ≈ KPS 70–80; ECOG 2 ≈ KPS 50–60; ECOG 3 ≈ KPS 30–40; ECOG 4 ≈ KPS 10–20. KPS is more granular (11 levels), making it better for capturing subtle functional changes, while ECOG is faster to assess and more widely used in clinical trial eligibility criteria.
Is the Karnofsky scale used outside of oncology?
In the context of Karnofsky Score, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of health and medical practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
Can KPS be used to predict survival?
Yes. Multiple studies demonstrate that KPS is a strong independent predictor of survival in cancer patients. The Palliative Performance Scale (PPS), which is derived from KPS, is specifically validated for survival prediction in palliative care settings. A KPS below 50 at diagnosis is associated with significantly shorter overall survival across most cancer types.
Is there a paediatric version of the Karnofsky scale?
In the context of Karnofsky Score, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of health and medical practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
Who should assess the Karnofsky score — clinician or patient?
In the context of Karnofsky Score, this depends on the specific inputs, assumptions, and goals of the user. The underlying formula provides a deterministic relationship between inputs and output, but real-world application requires interpreting the result within the broader context of health and medical practice. Professionals typically cross-reference calculator output with industry benchmarks, historical data, and regulatory requirements. For the most reliable results, ensure inputs are sourced from verified data, understand which assumptions the formula makes, and consider running multiple scenarios to bracket the range of likely outcomes.
What is the Palliative Performance Scale and how does it differ from KPS?
The Palliative Performance Scale (PPS) is a modified version of the KPS that adds assessment of ambulation, activity level, self-care, oral intake, and level of consciousness. It was specifically designed for palliative care populations and is validated for survival prediction in hospice settings. The PPS provides more granular information about the dimensions most relevant to end-of-life care.
プロのヒント
When a patient's KPS falls below 50 at a routine clinic visit, immediately review whether the decline is from disease progression, reversible toxicity, or untreated symptoms. Reversible causes (anaemia, pain, infection, electrolyte disturbance) identified and treated early can restore functional status and preserve treatment options.
ご存知でしたか？
The Karnofsky Performance Scale was published 75 years ago in a paper titled 'The Use of Nitrogen Mustards in the Palliative Treatment of Carcinoma.' David Karnofsky and Burchenal designed the scale as an afterthought to help standardise how they were reporting patient tolerance of the very first cancer chemotherapy agent ever used clinically. It is now cited in thousands of oncology papers annually.
参考文献
- ›Karnofsky DA, Burchenal JH. The clinical evaluation of chemotherapeutic agents in cancer. Columbia University Press 1949.
- ›Schag CC et al. Karnofsky performance status revisited: reliability, validity, and guidelines. J Clin Oncol 1984.
- ›Anderson F et al. Palliative Performance Scale (PPS): a new tool. J Palliat Care 1996.
- ›Lansky SB et al. Toward a standardization of pediatric cancer inpatient measurement. Cancer 1987.
- ›MDCalc — Karnofsky Performance Status