[Adverse events identified in medical complaints].

Background: "To err is human" (Institute of Medicine, 1999) begun the Patients' Safety movement worldwide. We undertook this study to determine the frequency of patient complaints related to adverse events in the National Health Services.

Methods: The National Commission of Medical Arbitration and the Vice-Ministry for Innovation and Quality has the aim of determining the frequency of real adverse events as a reason for complaints by patients and relatives against healthcare professionals and health services.

Results: The Emergency Department registered the highest number of events. Negligence and absence of protocols account for more than half of the adverse events.

Conclusions: Management protocols in emergency departments are areas of opportunity for improvement that must be considered.