Discussion
RECRUITMENT, DECAY
In this study, an observer tool (OT), based on chronological technical steps, was used with the aim of improving the training of incoming anesthesia residents to place a central venous catheter (internal jugular vein) during a simulation session. The use of an OT was not associated with better learning outcomes, immediately after the session and on reassessment, 1 month later.As learning from observing is likely more limited than active participation during simulation sessions [The absence of benefit reported in our present study could be explained by the fact that all the residents (with or without OT) had performed the task at least once on the task simulator. This active practice might have already improved their baseline skills (active education) thereby reducing the impact of the OT. Comparing groups of observers with or without OT but not practicing on the simulator might have potentiated the difference but ethical considerations precluded using this design. It is also possible that OT have differential impact based on clinical circumstances. They may be more appropriate for situations in which technical and non-technical skills are trained together [The available literature regarding the use of tools to increase observer learning is limited [Retention at 1 month was not only similar between groups but also similar to initial results. A similar number of procedures performed over the next month may explain this result. Comparing early and delayed results also revealed no difference. This was expected not only because trainees placed several CVCs during the following month, but also because the time interval was likely too short to identify any decay in knowledge. Any difference could also have been masked by the limited number of residents filling adequately their logbook, reducing the statistical power. We anticipated limited protocol compliance and therefore offered a well-known anesthesia book as incentive to complete the whole study. Offering a material or financial incentive is a well-known factor that can increase recruitment [Transfer of learning (i.e. levels 3 and 4 of the Kirkpatrick model [The strengths of this study included the fact that our study was prospective and randomized and that we used a previously validated CVC insertion grid [However, it also has several limitations. All participating residents (with or without OT) performed at least one CVC placement on the simulator during the session and this may have masked any additional effects of the tool.The use of a composite score to assess learning might have limited the validity of our results. However, this score has been used in one of our previous studies [