Also known as Karnofsky Performance Status, KPS, Karnofsky score, performance status
Clinician-assigned functional status level, 0 to 100.
Applies to / doesn’t apply to3
Applies to: Adults with cancer, the population the scale was developed in and is most studied in. It is also recorded in palliative care, where modified versions were derived from it (Abernethy 2005), and in US transplant registries at listing and after transplant (Chu 2021).
- Children. A separate, parent-rated play-performance scale was developed for children with cancer (Lansky 1987), and the FDA’s 2026 guidance notes that performance status may be based on a different scale for younger paediatric patients.
- As a determination of treatment, clinical-trial or transplant eligibility. Thresholds are rules written against the score, not its clinical meaning. The FDA’s 2026 guidance states that patients with ECOG PS 2 (or KPS 60–70) should be included in trials unless there is a scientific and/or clinical rationale for exclusion.
- To derive an ECOG grade for an individual patient. Translating one scale to the other for an individual carries a high level of error (Verger 1992).
Choose the one description that best fits the patient’s current activity and need for care. Pick the description, not a number.
What this score estimates
Records which of the published Karnofsky Performance Status descriptions a clinician judges best fits a patient’s current activity and need for care, on the scale introduced by Karnofsky and Burchenal in 1949. There is no formula: the clinician selects one description and its level, 0 to 100 in steps of 10, is the result; 0 is dead. Lower levels describe progressively less activity and more need for assistance and medical care. It describes function at a single point in time — it is not a prognosis, not a measure of disease severity, and not a determination of eligibility for treatment, a clinical trial or transplant listing.
Pearls & pitfalls
13
- Reliability depends on who rates and how. Inter-rater reliability among 47 interviewers trained in scoring guidelines was 0.97 (Mor 1984), while earlier studies described it as moderately high (Yates 1980) and identified areas in which physicians err in their judgements (Schag 1984). These used different designs and are not one figure for the scale.
- The setting moves the score: patients evaluated at home were usually given a lower score than in a clinic evaluation at the same time (Yates 1980).
- A low score was associated with early death, but a high initial score did not necessarily predict long survival (Yates 1980); the correlation with survival in terminal cancer was r = 0.30 (Mor 1984).
- The lower descriptions tie function to hospital care (“hospital admission is indicated”, “hospital admission necessary”), which reflects the more limited care options of the 1940s (Péus 2013); a 2005 palliative-care study found the greatest disagreement with a setting-neutral modification at levels 40 and below (Abernethy 2005).
- In one single-institution lung-cancer study, KPS discriminated prognosis less well than ECOG (Buccheri 1996).
- Approximate, research-derived correspondence with ECOG — a reference note, not a conversion. In 1,385 assessments of patients with advanced cancer, the grouping KPS 100 ≈ ECOG 0, 80–90 ≈ 1, 60–70 ≈ 2, 40–50 ≈ 3 and 10–30 ≈ 4 matched the separately assigned ECOG grade in 75% of cases (Ma 2010). Other mappings circulate — a coarser three-group table agreed in over 84% of cases in a 536-patient lung-cancer study (Buccheri 1996) — and translating an individual patient’s score from one scale to the other carries a high level of error (Verger 1992). The grouping covers living patients only; both scales end at death, as KPS 0 and ECOG 5.
Risk factors the score does not count:
- Comorbidity
- Cognition
- Symptom burden, including pain
- The cause of a low score — cancer, treatment toxicity, or an unrelated condition
- The patient’s own assessment of their function
- Change over time, or the rate of change
- Any laboratory value, vital sign, age or sex
What the guidelines say
2
Names ECOG and Karnofsky as the two main performance-status scales in cancer trial eligibility, describes low performance status as ECOG PS 2–4 and KPS 70 or below, and states that patients with ECOG PS 2 (or KPS 60–70) should be included unless there is a scientific and/or clinical rationale for exclusion justified by established safety considerations.
View guideline source ↗Publishes the Karnofsky Performance Status Scale as a public-domain clinical classification for clinical-trial data, with the eleven level descriptions reproduced here, citing Karnofsky and Burchenal 1949.
View guideline source ↗Guideline positions are stated as published. Curie.MD Calc does not publish treatment direction.
Where this comes from
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References
- Karnofsky DA, Burchenal JH. The clinical evaluation of chemotherapeutic agents in cancer. In: MacLeod CM, ed. Evaluation of Chemotherapeutic Agents. New York: Columbia University Press; 1949:191-205. Book chapter (Columbia University Press, 1949) with no DOI and no open online copy.
- Karnofsky DA, Abelmann WH, Craver LF, Burchenal JH. The use of the nitrogen mustards in the palliative treatment of carcinoma. With particular reference to bronchogenic carcinoma. Cancer. 1948;1(4):634-656. View source ↗
- CDISC Controlled Terminology (NCI EVS), Karnofsky Performance Status Scale clinical classification KPSS01, original response codelist C182469; CDISC QRS "Karnofsky Performance Scale", permission: Public Domain. Accessed 2026-10-19. View source ↗
- Yates JW, Chalmer B, McKegney FP. Evaluation of patients with advanced cancer using the Karnofsky performance status. Cancer. 1980;45(8):2220-4. View source ↗
- Schag CC, Heinrich RL, Ganz PA. Karnofsky performance status revisited: reliability, validity, and guidelines. J Clin Oncol. 1984;2(3):187-93. View source ↗
- Mor V, Laliberte L, Morris JN, Wiemann M. The Karnofsky Performance Status Scale. An examination of its reliability and validity in a research setting. Cancer. 1984;53(9):2002-7. View source ↗
- Péus D, Newcomb N, Hofer S. Appraisal of the Karnofsky Performance Status and proposal of a simple algorithmic system for its evaluation. BMC Med Inform Decis Mak. 2013;13:72. View source ↗
- Abernethy AP, Shelby-James T, Fazekas BS, Woods D, Currow DC. The Australia-modified Karnofsky Performance Status (AKPS) scale: a revised scale for contemporary palliative care clinical practice. BMC Palliat Care. 2005;4:7. View source ↗
- Ma C, Bandukwala S, Burman D, et al. Interconversion of three measures of performance status: an empirical analysis. Eur J Cancer. 2010;46(18):3175-83. View source ↗
- Buccheri G, Ferrigno D, Tamburini M. Karnofsky and ECOG performance status scoring in lung cancer: a prospective, longitudinal study of 536 patients from a single institution. Eur J Cancer. 1996;32A(7):1135-41. View source ↗
- Verger E, Salamero M, Conill C. Can Karnofsky performance status be transformed to the Eastern Cooperative Oncology Group scoring scale and vice versa? Eur J Cancer. 1992;28(8-9):1328-30. View source ↗
- Lansky SB, List MA, Lansky LL, Ritter-Sterr C, Miller DR. The measurement of performance in childhood cancer patients. Cancer. 1987;60(7):1651-6. View source ↗
- Chu NM, Chen X, Bae S, et al. Changes in functional status among kidney transplant recipients: data from the Scientific Registry of Transplant Recipients. Transplantation. 2021;105(9):2104-2111. View source ↗
- US Food and Drug Administration. Cancer clinical trial eligibility criteria: performance status. Guidance for industry, IRBs, and clinical investigators. July 2026. View source ↗