Safer Surgery part 30. 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. | 264 Safer Surgery Table Description of domains behavioural markers of team behaviour assessed by the observers Behavioural Marker Domain Description Used in univariate analysis and calculation of Behavioural Marker Risk Index Briefing Situation relevant background shared patient procedure site side identified plans are stated questions asked ongoing monitoring and communication encouraged Information sharing Information is shared intentions are stated mutual respect is evident social conversations are appropriate Inquiry Asks for input and other relevant information Vigilance and awareness Tasks are prioritized attention is focused patient equipment monitoring is maintained tunnel vision is avoided red flags are identified Not used in univariate analysis calculation of Behavioural Marker Risk Index Assertion The members of the team are speaking up with their observations and recommendations during critical times Contingency management Relevant risks are identified back-up plans are made and executed Adjustment Variables and Outcomes The American Society of Anesthesiologists ASA score assigned by the anaesthesiologist was recorded. The ASA score subjectively categorizes patients into five sub-groups by preoperative physical fitness and appear in Table Mazzocco et al. 2008 . The ASA score was devised in 1941 by the ASA as a statistical tool for retrospective analysis of hospital records and has been revised periodically Walker 2002 . In nine patients the ASA score was not recorded in either the medical record or on the observation sheet. In these cases an anaesthesiologist independent of the study reviewed information on patient characteristics obtained from the medical record review and assigned an ASA score. The surgical procedures were classified as low medium or high risk for post-operative complications according to American College of Cardiology and American Heart Association guidelines Eagle et al. 2002 . Low risk procedures included biopsy excision
