[What is the meaning of safety in hospitals?].

Patient safety in hospitals is difficult to define and is not measurable by operational safety parameters as in other fields. So-called adverse events (AE) are a collective of complications, failures, mistakes, errors and violations. Estimations of at least 9.2 % AEs in surgery with 0.1 % fatalities are given worldwide but there are no correlations between objective quantification of AEs and subjective or public perception of safety during the perioperative period. Patient safety during this period is mostly endangered by wound infections (safety 98 %) and nosocomial infections (safety 97 %). In spite of these facts, safety parameters for problems in anesthesia, blood transfusion, in retaining surgical instruments and so-called index events, such as patient and side identification errors are much higher. Patient safety is maintained in hospitals by objective means (surgical). Checklists have been proven to improve safety and critical incidence reporting, training and changing of attitudes could have further advantages but they are difficult to measure.