Search tips
Search criteria 


Logo of brjcancerBJC HomepageBJC Advance online publicationBJC Current IssueSubmitting an article to BJCWeb feeds
Br J Cancer. 1993 April; 67(4): 773–775.
PMCID: PMC1968363

Performance status assessment in cancer patients. An inter-observer variability study.


The ECOG Scale of Performance Status (PS) is widely used to quantify the functional status of cancer patients, and is an important factor determining prognosis in a number of malignant conditions. The PS describes the status of symptoms and functions with respect to ambulatory status and need for care. PS 0 means normal activity, PS 1 means some symptoms, but still near fully ambulatory, PS 2 means less than 50%, and PS 3 means more than 50% of daytime in bed, while PS 4 means completely bedridden. An inter-observer variability study of PS assessment has been carried out to evaluate the non-chance agreement among three oncologists rating 100 consecutive cancer patients. Total unanimity was observed in 40 cases, unanimity between two observers in 53 cases, and total disagreement in seven cases. Kappa statistics reveal the ability of the observers compared to change alone and were used to evaluate non-chance agreement. Overall Kappa was 0.44, (95% confidence limits 0.38-0.51). The Kappa for PS 0 was 0.55 (0.44-0.67), while those for PS 1, 2, 3 and four were 0.48 (0.37-0.60), 0.31 (0.19-0.42), 0.43 (0.32-0.55), and 0.33 (0.33-0.45), respectively. If one observer allocated patients to PS 0-2, then another randomly selected observed placed the patients in the same category with a probability of 0.92. For patients with PS 3-4 the probability that the same category would be chosen was 0.82. Overall, the non-chance agreement between observers was only moderate, when all ECOG Performance Status groups were considered. However, agreement with regard to allocation of patients to PS 0-2 versus 3-4 was high. This is of interest because this cut-off is often used in clinical studies.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (633K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Conill C, Verger E, Salamero M. Performance status assessment in cancer patients. Cancer. 1990 Apr 15;65(8):1864–1866. [PubMed]
  • Conn HO, Spencer RP. Observer error in liver scans. Gastroenterology. 1972 May;62(5):1085–1090. [PubMed]
  • Ganz PA, Haskell CM, Figlin RA, La Soto N, Siau J. Estimating the quality of life in a clinical trial of patients with metastatic lung cancer using the Karnofsky performance status and the Functional Living Index--Cancer. Cancer. 1988 Feb 15;61(4):849–856. [PubMed]
  • Hutchinson TA, Boyd NF, Feinstein AR, Gonda A, Hollomby D, Rowat B. Scientific problems in clinical scales, as demonstrated in the Karnofsky index of performance status. J Chronic Dis. 1979;32(9-10):661–666. [PubMed]
  • Koran LM. The reliability of clinical methods, data and judgments (first of two parts). N Engl J Med. 1975 Sep 25;293(13):642–646. [PubMed]
  • Lund B, Williamson P, van Houwelingen HC, Neijt JP. Comparison of the predictive power of different prognostic indices for overall survival in patients with advanced ovarian carcinoma. Cancer Res. 1990 Aug 1;50(15):4626–4629. [PubMed]
  • 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 May 1;53(9):2002–2007. [PubMed]
  • Schag CC, Heinrich RL, Ganz PA. Karnofsky performance status revisited: reliability, validity, and guidelines. J Clin Oncol. 1984 Mar;2(3):187–193. [PubMed]
  • Schipper H, Clinch J, McMurray A, Levitt M. Measuring the quality of life of cancer patients: the Functional Living Index-Cancer: development and validation. J Clin Oncol. 1984 May;2(5):472–483. [PubMed]
  • SEGALL HN. The electrocardiogram and its interpretation: a study of reports by 20 physicians on a set of 100 electrocardiograms. Can Med Assoc J. 1960 Jan 2;82:2–6. [PMC free article] [PubMed]
  • Slevin ML, Plant H, Lynch D, Drinkwater J, Gregory WM. Who should measure quality of life, the doctor or the patient? Br J Cancer. 1988 Jan;57(1):109–112. [PMC free article] [PubMed]
  • Spitzer RL, Fleiss JL. A re-analysis of the reliability of psychiatric diagnosis. Br J Psychiatry. 1974 Oct;125(0):341–347. [PubMed]
  • Swenerton KD, Legha SS, Smith T, Hortobagyi GN, Gehan EA, Yap HY, Gutterman JU, Blumenschein GR. Prognostic factors in metastatic breast cancer treated with combination chemotherapy. Cancer Res. 1979 May;39(5):1552–1562. [PubMed]
  • Sørensen JB, Badsberg JH, Olsen J. Prognostic factors in inoperable adenocarcinoma of the lung: a multivariate regression analysis of 259 patients. Cancer Res. 1989 Oct 15;49(20):5748–5754. [PubMed]
  • Wood CA, Anderson J, Yates JW. Physical function assessment in patients with advanced cancer. Med Pediatr Oncol. 1981;9(2):129–132. [PubMed]
  • Yates JW, Chalmer B, McKegney FP. Evaluation of patients with advanced cancer using the Karnofsky performance status. Cancer. 1980 Apr 15;45(8):2220–2224. [PubMed]
  • Osterlind K, Andersen PK. Prognostic factors in small cell lung cancer: multivariate model based on 778 patients treated with chemotherapy with or without irradiation. Cancer Res. 1986 Aug;46(8):4189–4194. [PubMed]

Articles from British Journal of Cancer are provided here courtesy of Cancer Research UK