Are prehospital deaths from trauma and accidental injury preventable? A summary report 13 2 Design hile commissioning the study, the researchers reported that a different approach to the analysis W of probability of survival was required. They proposed a refined methodology to account for updates to both the Abbreviated Injury Scale (AIS) and the calculation of the probability of survival. As these adaptations meant a direct historical comparison would not be possible, we decided to commission two related studies. Study one used the same methodology as the original 1994 study and applied this to more recent coroners’ records. Study two used the updated AIS and calculation for the probability of survival. Both analysed case records. Both studies are authored by Oliver, Walter and Redmond and, at the time of publishing this summary report, have been submitted to a specialist journal for publication.