BackgroundThe Scrub Practitioners’ List of Intraoperative Non-Technical Skills (SPLINTS) system is a new tool for training and assessing scrub practitioner (nurse, technician) behaviours during surgical operations. ObjectivesThe aim of the study was to test the psychometric properties including inter-rater reliability of the prototype SPLINTS behavioural rating system. MethodsExperienced scrub practitioners (n=34) attended a one-day session where they received background training in human factors and non-technical skills and were also trained to use the SPLINTS system. They then used SPLINTS to rate the scrub practitioners’ non-technical skill performance in seven standardized simulated, surgical scenarios. ResultsReliability, measured by within-group agreement (rwg) for the three skill categories and six out of nine elements, was acceptable (rwg>0.7). Participants were within one scale point of expert ratings in >90% of skill categories and elements, and could use SPLINTS to score performance with a reasonable level of accuracy. There was good internal consistency of the system: absolute mean difference was M<0.2 of a scale point for all three categories. Participants were surveyed and they indicated that the system was complete and usable as an assessment tool. ConclusionThe reliability of the SPLINTS system was deemed to be adequate for assessing scrub practitioners’ non-technical skills in simulated, standardized, video scenarios. On the basis of these results, the system can now move on to usability testing in the real operating theatre.