Table 1 Categories of medical errors and severity of reported errors

.Incorrect choice of therapy

.Wrong diagnostic test

.Misdiagnosis leading to an incorrect choice of therapy

.Use of outmoded tests or therapy

.Misinterpretation of test results

.Failure to do the indicated diagnostic tests

.Failure to act on results of monitoring or testing

.Reception of the wrong drug

.Inappropriate care

.Error in the administration of the treatment

.Error in the dose or method of using a drug leading to the patient’s death

.Delay in treatment

.Failure to provide prophylactic treatment

.Inadequate monitoring or follow-up of treatment

.Failure in communication (inadequate informed consent)

.Equipment or system failure

 No harm

Minor errors

.Any medical error that had the potential to cause harm but was prevented, resulting in no harm to patient

 Mild harm

.Any unexpected or unintended incident that required extra observation or minor treatment and caused minimal harm to one or more persons

 Moderate harm

Serious errors

.Any unexpected or unintended incident that resulted in further treatment, possible surgical intervention, cancelling of treatment, or transfer to another area, and which caused short-term harm to one or more persons

 Severe harm

.Any unexpected or unintended incident that caused permanent or long-term harm to one or more persons

 Not assessable