Table 1

Some definitions of adverse events drawn from the literature

McLamb and Huntley (1967)¹²	“Any response to medical care in the hospital that is unintended, undesirable and harmful to the patient.”
Mills (1978)⁹	“A potentially compensable event is a disability caused by health care management:
	• Disability—is a temporary or permanent impairment of physical or mental function (including disfigurement) or economic loss
	• Causation—is established when the disability is more probably than not attributable to health care management
	• Healthcare management—includes both actions and inactions of any healthcare provider or attendant.”
Craddick and Bader (1983, p23)¹³	“Adverse patient occurrences (APOs) ... refer to untoward patient events which, under optimal conditions, are not a natural consequence of the patient's disease or treatment. The common thread of all APOs is that they are events which health professionals agree are not desirable outcomes of medical management.”
Harvard Medical Practice Study (1990)¹⁰	“An unintended injury caused by medical management rather than by the disease process. The injury is sufficiently serious to lead to prolongation of hospitalisation or temporary or permanent impairment or disability in the patient.”
Wilson RM et al (1995)¹⁴	“An unintended injury or complication which results in disability, death or prolonged hospital stay and is caused by health care management.”
Walshe (1998)¹⁵	“An untoward or undesirable occurrence in the healthcare process which has or potentially has some negative impact on a patient or patients and results or may result from some part of the healthcare process.”