The Apache (; ) are culturally related Native American tribes from the Southwestern United States and Northern Mexico. These indigenous peoples of North America speak Southern Athabaskan languages, which are related linguistically to Athabaskan languages in Alaska and western Canada.

APACHE II ("Acute Physiology and Chronic Health Evaluation II") is a severity-of-disease classification system (Knaus et al., 1985), one of several ICU scoring systems. It is applied within 24 hours of admission of a patient to an intensive care unit (ICU): an integer score from 0 to 71 is computed based on several measurements; higher scores correspond to more severe disease and a higher risk of death. The first APACHE model was presented by Knaus et al. in 1981.