Cure

A cure is a substance or procedure that ends a medical condition, such as a medication, a surgical operation, a change in lifestyle or even a philosophical mindset that helps end a person's sufferings; or the state of being healed, or cured. The medical condition could be a disease, mental illness, genetic disorder, or simply a condition a person considers socially undesirable, such as baldness or lack of breast tissue. An incurable disease may or may not be a terminal illness; conversely, a curable illness can still result in the patient's death. The proportion of people with a disease that are cured by a given treatment, called the cure fraction or cure rate, is determined by comparing disease-free survival of treated people against a matched control group that never had the disease. Another way of determining the cure fraction and/or "cure time" is by measuring when the hazard rate in a diseased group of individuals returns to the hazard rate measured in the general population. Inherent in the idea of a cure is the permanent end to the specific instance of the disease. When a person has the common cold, and then recovers from it, the person is said to be cured, even though the person might someday catch another cold. Conversely, a person that has successfully managed a disease, such as diabetes mellitus, so that it produces no undesirable symptoms for the moment, but without actually permanently ending it, is not cured. Related concepts, whose meaning can differ, include response, remission and recovery. In complex diseases, such as cancer, researchers rely on statistical comparisons of disease-free survival (DFS) of patients against matched, healthy control groups. This logically rigorous approach essentially equates indefinite remission with cure. The comparison is usually made through the Kaplan-Meier estimator approach. The simplest cure rate model was published by Joseph Berkson and Robert P. Gage in 1952.