Korrelationen mellan fotgängares skador i verkliga olyckor och Euro NCAPs testresultat för fotgängarskydd

Sammanfattning: The aim of the present study was to estimate the correlation between Euro NCAP pedestrian rating scores and injury outcome in real-life car to pedestrian crashes, with special focus on long-term disability. The study also surveyed most frequently injured body regions and risk differences for specific elements of pedestrians hit by cars. Another aim was to determine whether Brake Assist systems affect the injury outcome in real-life car to pedestrian crashes and to estimate the effect in injury reduction of a high Euro NCAP ranking score combined with Brake Assist. In the current study, the Euro NCAP pedestrian scoring was compared with the real-life outcome in pedestrian crashes that occurred in Sweden 2003-2010. The real-life crash data was obtained from the data acquisition system STRADA, which combines police records and hospital admission data. The medical data consisted of International Statistical Classification of Diseases and Related Health Problems (ICD) diagnoses and Abbreviated Injury Scale (AIS) scoring. In all approximately 500 pedestrians submitted to hospital were included in the study. Each car model was coded according to Euro NCAP pedestrian scores. In addition, the presence or absence of Brake Assist (BA) was coded for each car involved. Pedestrians were grouped according to associated car scoring. Injury outcomes were analyzed with AIS and, at victim level, with permanent medical impairment. This was done by translating the injury scores for each individual to Risk of Serious Consequences (RSC) at 1, 5 and 10% level of medical disability or more. This indicates the total risk of a medical disability for each victim, given the severity and location of injuries. The mean RSC (mrsc) was then calculated for each pedestrian group and t-tests were conducted to ensure statistically significant differences in mrsc between groups. The results showed a significant reduction of injury severity for pedestrians hit by cars with better pedestrian scoring, although pedestrians hit by cars with a high score (three or four stars) could not be studied, due to lack of cases. The reduction of RSC for pedestrians hit by medium performing (two-star) cars in comparison with pedestrians hit by low performing (one-star) cars was 12, 19 and 28% for 1 ,5 and 10% of medical impairment or more, respectively. These results applied to speed limits up to 90 km/h. In urban areas with speed limits up to 50 km/h the reduction of RSC was 17, 26 and 38% for 1, 5 and 10% of medical impairment or more, respectively. Car to pedestrian crashes was most common at speed limits up to 50 km/h and leg, arm and head were the most frequently injured body regions. RSC for pedestrians hit by cars with Brake Assist was not statistically significant lower than for pedestrians hit by cars without Brake Assist. RSC for pedestrians hit by two-star cars with Brake Assist was 19, 31 and 46% lower for 1, 5 and 10% of medical impairment or more, respectively, compared to pedestrians hit by one-star cars without Brake Assist. A significant correlation between Euro NCAP pedestrian score and injury outcome in real-life car to pedestrian crashes was found. The injury reduction was found to be larger for higher severity and level of permanent medical impairment. Car to pedestrian crashes was most common at lower speed zones. Leg, arm and head were the most frequently injured body regions. Brake Assist had no statistically significant effect measured in RSC on car to pedestrian crashes in this material. A high Euro NCAP scoring combined with Brake Assist was shown to give a high effect in reduction of RSC for pedestrians.