Defining Terms in Patient Safety

Adverse event
An adverse event is an injury cause by medical management rather the underlying condition of the the patient.  (From the IOM report:  To Err is Human.)

Adverse drug event (ADE)
An injury resulting from medical intervention related to a drug.  Adverse drug events include adverse drug reactions.

Adverse drug reaction (ADR)
A reaction to a drug which is noxious and unintended.  The reaction occurs in doses normally used for the prophylaxis, diagnosis, or therapy of disease.  (From the Food and Drug Administration)  All adverse events or reactions involve patient injury.

Error
All those occasions in which a planned sequence of mental or physical activities fails to achieve its intended outcome.  (From:  James Reason, Human Error, 1990.)

Near Miss Event
Term used to describe any process variation that did not affect an outcome but for which a recurrence carries a significant chance of a serious adverse outcome.

Negligent adverse events
A subset of preventable adverse events that satisfy legal criteria used in determining negligence (i.e., whether the care provided failed to meet the standard of care reasonably expected of an average physician qualified to take care of the patient in question).  (From the IOM report:  To Err is Human.)

Patient safety
“…. the avoidance, prevention, and amelioration of adverse outcomes or injuries stemming from the processes of healthcare.”  (From the National Patient Safety Foundation)  Safety can also be defined as “freedom from accidental injury.”  (From the IOM report:  To Err is Human.)

Safety has multiple dimensions, including:

• an outlook that recognizes that health care is complex and risky and that solutions are found in the broader systems context;
• a set of processes that identify, evaluate, and minimize hazards and are continuously improving; and
• an outcome that is manifested by fewer medical errors and minimized risk or hazard.

(From the VHA’s Patient Safety Improvement Inititative as cited in the IOM report)

Preventable adverse event
An adverse event attributable to error  (From the IOM report:  To Err is Human.)

Sentinel Event
An adverse event that results in the loss of life or limb or permanent loss of function.  Includes death resulting from a medication error, or assaults and suicides by patients who received services from the medical facility within the prior 30 days.