A death is considered preventable when the patient received poor care, and the poor care probably resulted in the patient’s death.

182 patients who died in hospitals from stroke, pneumonia, or heart attack.

Medical records for patients from 12 hospitals, 1985.

14% of deaths resulted from inadequate diagnosis or treatment and could have been prevented.

Dubois and Brook, 1988

An adverse event is an injury that is caused by medical management rather than the underlying disease and that prolongs hospitalization, produces a disability at

discharge, or both.

30,121 medical records from a weighted sample of 31,429 records of hospitalized patients from a population of 2,671,863 nonpsychiatric discharged patients.

51 randomly selected acute care, nonpsychiatric hospitals in New York State, 1984.

There were 1,133 adverse events and 280 negligent events during 1984 admissions, representing a 3.7% statewide incidence rate of adverse events, and a 1.0% statewide incidence rate of adverse events due to negligence.

Brennan et al., 1991