The Full Form of ECOG is Eastern Cooperative Oncology Group.

To conduct clinical trials for the treatment of cancer in a consistent manner across many participating hospitals, cancer centers, and clinics requires the use of standard criteria for measuring how the disease impacts a patient’s daily living abilities (known to physicians and researchers as a patient’s performance status). The ECOG Scale of Performance Status is one such measurement. It describes a patient’s level of functioning in terms of their ability to care for themself, daily activity, and physical ability (walking, working, etc.).

Researchers worldwide take the ECOG Performance Status into consideration when planning trials to study a new treatment method. This numbering scale is one way to define the population of patients to be studied in the trial, so that it can be uniformly reproduced among physicians who enroll patients. It is also a way for physicians to track changes in a patient’s level of functioning as a result of treatment during the trial.

The scale was developed by the Eastern Cooperative Oncology Group (ECOG), now part of the ECOG-ACRIN Cancer Research Group, and published in 1982. It circulates in the public domain and is therefore available for public use. It is displayed below both for future reference and to spur further standardization among researchers who design and evaluate cancer clinical research.