Safer Surgery part 32. There have been few research investigations into how highly trained doctors and nurses work together to achieve safe and efficient anaesthesia and surgery. While there have been major advances in surgical and anaesthetic procedures, there are still significant risks for patients during operations and adverse events are not unknown. Due to rising concern about patient safety, surgeons and anaesthetists have looked for ways of minimising adverse events. | 284 Safer Surgery Researchers studying OR team performance have sought to address this deficit by developing tools that include in their purview the objective evaluation of team communication Salas et al. 2007 Undre et al. 2007 . Our recent research in the OR has elaborated a theory of interprofessional team communication that describes tension catalysts reveals interpretive patterns and classifies recurrent failures Lingard et al. 2002c 2002b 2004 . This work suggests clear directions for educational interventions aimed at improving the status quo of OR communication practices Lingard et al. 2005 . Assessing the effectiveness of such interventions requires appropriate measures of team communication. The challenge in creating such measures is to provide analytical traction while continuing to reflect the complex often subtle and evolving nature of team communication. Our Communication Failures Tool To address this measurement need we developed a theory-based instrument that reflected the findings of our observational research Lingard et al. 2006 . The instrument is a checklist of types of communication failure and their outcomes based on our classification of communication failure in the OR framed by rhetorical theory Lingard et al. 2004 . Four communication failure types are tracked by the instrument occasion content purpose and audience see Table . Occasion involves communication problems related to time and space. For instance a common timing problem is the surgeon s request for a special piece of equipment at the moment of need rather than before the procedure commences assuming the need for the equipment could be foreseen . Content failures consist of communicative exchanges that contain incomplete or inaccurate information such as a nurse s inaccurate announcement that a patient was positive for hepatitis C. The Purpose category includes situations in which questions are asked but not answered prompting repeated and increasingly urgent requests. Finally
