Nature, causes and consequences of unintended events in surgical units (Br J Surg 2010; 97: 1730-1740).

BACKGROUND Several studies have shown that the rate of unintended harm is higher in surgical than in non-surgical care. To improve patient safety in surgery, information about the underlying causes is needed. This observational study examined the nature, causes and consequences of unintended events in surgical units, and the completeness of event reporting. METHODS Ten surgical units in the Netherlands participated. The study period per unit was 8-14 weeks, during which healthcare providers reported unintended events. Event reports were analysed with a root cause analysis tool (PRISMA). In addition, an independent surgeon reviewed about 40 patient records of patients in each surgical unit to examine whether an unintended event had occurred. RESULTS A total of 881 unintended events were reported and analysed, of which 33.0 per cent were categorized as medication events. Most root causes were human (72.3 per cent), followed by organizational (16.1 per cent) and technical (5.7 per cent). More than half of the events had consequences for the patient. Sixty-four unintended events were identified in a review of 320 patient records. Only one of these events was also reported by a healthcare provider. CONCLUSION Event reporting and patient record review provide insight into diverse types of unintended events and complement each other. The information on unintended events from both sources may help target research and interventions to increase patient safety.