Ecog Performance Status Calculator

ECOG Performance Status compresses a patient's functional capacity onto a six-point ordinal scale. Grade 0 is full activity without restriction; grade 1 is restriction of strenuous activity with preserved light or sedentary work; grade 2 is full self-care but no work capacity, with more than half of waking hours out of bed; grade 3 is limited self-care with more than half of waking hours in bed or chair; grade 4 is complete disability; grade 5 is death. The anchor carrying most of the discrimination is the proportion of waking hours spent in bed or chair, which is why grades 2 and 3 divide at 50 percent. Approximate Karnofsky equivalents run from 90 to 100 at grade 0 down to 10 to 20 at grade 4. The score is among the strongest independent predictors of survival in oncology and often outweighs histology or stage in deciding whether systemic therapy is appropriate. In advanced non-small cell lung cancer, median survival on standard chemotherapy falls from roughly 12 months at grade 0 to about 4 to 6 months at grade 2. Most phase II and phase III trials require grade 0 or 1, creating a well-documented gap between trial populations and real-world patients. Reliability is the main weakness: inter-observer kappa is typically 0.5 to 0.7, agreement is worst between grades 1 and 2, and oncologists systematically rate patients as more functional than nurses or the patients themselves do.

The scale originated with C. Gordon Zubrod, then at the National Cancer Institute, who needed a uniform way to describe patients across institutions in a comparative trial of nitrogen mustard and thiotepa. The 1960 report of that trial in the Journal of Chronic Diseases included a five-level performance rating, and the instrument is still sometimes called the Zubrod scale. Its purpose was narrowly practical: cooperative group trials of the 1950s had produced incompatible descriptions of how sick enrolled patients were, which made comparison across studies close to meaningless. The Eastern Cooperative Oncology Group, founded in 1955 as one of the first National Cancer Institute cooperative groups, adopted and propagated the scale, and Martin Oken and colleagues published the version in general use today as part of the group's toxicity and response criteria in the American Journal of Clinical Oncology in 1982. The World Health Organization incorporated the same criteria into its 1979 handbook for reporting results of cancer treatment, which is why ECOG, WHO, and Zubrod performance status all refer to the same set of grades. ECOG merged with the American College of Radiology Imaging Network in 2012 to form ECOG-ACRIN, which maintains the currently published definitions.