Where does accident collide?

A feature that a thing happens to have but could lose while remaining the same kind of thing, as opposed to a feature that belongs to its essence. Aristotle's Categories (ca. 350 B.C.E.) and later Metaphysics drew this contrast: a man may be pale or seated, but he would still be a man without those features, so they are accidental, whereas being a rational animal is not. The referent here is a mode of predication, a property held contingently by a substance, and it has nothing to do with an unintended harmful event, an industrial loss, or an injury to the brain.[1]

Unit

A single property predicated of a substance, held contingently rather than essentially

Recovery means

Not applicable

Measured by

Identified by analysis, by asking whether the thing would remain the same kind of thing without the property

An unplanned event that results in injury or damage, understood as the end of a chain of causes that can be identified and broken before the next one occurs. Heinrich's Industrial Accident Prevention (1931) modeled this as a row of falling dominoes and attributed most workplace accidents to unsafe acts and conditions; Reason's later account of organizational accidents (2000) recast the chain as layers of defenses whose gaps line up. The referent is a preventable loss event studied to stop it recurring, which is close to the legal meaning yet flips its stance: where the law can call an event a pure accident with no one at fault, this field holds that every accident has traceable causes.[2][3]

Unit

A single unplanned loss event, scaled by its frequency and its severity

Recovery means

Not applicable

Measured by

Counted as incident rates, by the frequency and severity of recordable injuries, and analyzed by root-cause methods

A stroke, long called a cerebrovascular accident, is the sudden injury or death of brain tissue caused by an interruption of its blood supply, either a blockage (ischemic) or a bleed (hemorrhagic). The American Heart Association and American Stroke Association consensus definition (Sacco et al., 2013) sets out the current clinical and tissue-based criteria. In this phrase the word carries its older idea of a sudden event that befalls a patient, and many clinicians now prefer the word stroke because the event has identifiable causes and risk factors. The referent is a specific pathological event in the brain, distinct from a contingent property, a question of legal fault, or an industrial loss event.[4]

Unit

A single episode of brain injury from disrupted cerebral blood flow

Recovery means

Rehabilitation and neurological recovery vary with the extent and location of the tissue injury

Measured by

Diagnosed clinically and by neuroimaging (CT or MRI) and classified by mechanism as ischemic or hemorrhagic