Discussion In order to avoid outcome reporting bias and data driven results this paper presents the detailed statistical analysis plan for the main publication of the DIFFICAIR trial. The DIFFICAIR trial raises two important questions i.e. is it possible via the intervention to reduce the frequency of difficult intubation and/or difficult mask ventilation? This plan only addresses the statistical analysis of the population of intubated patients. This is because our sample size calculations were based on the same population; the SARI was developed as a prediction tool for difficult intubation; and due to the extent of data.