Table 1 Terminology and definitions used to describe hazards and/or harm in patient care

Patient safety incident: event or circumstance that could have resulted in, or did result in, unnecessary harm to a patient

Adverse event (harmful incident):

   • Injury or harm related to (or from) the delivery of care (Institute of Healthcare Improvement)

   • A patient safety incident; undesirable health event that may or may not be related to the treatment

   • Any injury due to medical management, rather than to the underlying disease [28]

   • In several studies: an incident that resulted in death, life-threatening illness, disability at time of discharge, admission to hospital or prolongation of hospital stay

Medical error:

   • An adverse event that is preventable, inaccurate or incomplete diagnosis and/or treatment

   • Failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim [28]

Sentinel event (Joint Commission on Accreditation of Healthcare Organizations): a serious medical error; any unanticipated event in a healthcare setting resulting in death or serious physical or psychological injury

Never event: a serious reportable event; occurrence that should never happen in a hospital and can be prevented

Near miss: a patient safety incident; event or situation that could have resulted in an accident, injury or illness but did not, either by chance or through timely intervention

Critical incident: adverse event with the potential to harm patients, staff or visitors [45]

Complication: unfavorable evolution of a disease, health condition or medical treatment