425 An Analysis of Distance From Collision Site to Pedestrian Home Residence in Pedestrian versus Automobile Collisions Presenting to a Level I Trauma Center

Abstract

Pedestrian injuries continue to be a significant world burden of disease. Current literature suggests most child pedestrians are injured by automobiles close to home or school. Yet, there continues to be a paucity of literature examining adult ped-auto collisions and proximity to home. Our current project aims to test the hypothesis that most pedestrian collisions occur near victims' homes. This study explores various individual and neighborhood-level characteristics associated with pedestrian collisions presenting as traumas in a culturally diverse area and describes characteristics of patients most likely to be struck closer to home. We also analyzed ISS scores and poverty levels in relation to distance from collision site to home. A retrospective study design was employed using data from the trauma registry of a major university level I trauma center. Included were pedestrians injured in auto versus pedestrian collisions that presented to the ED over a 5-year period, 2005 to 2009, inclusive (n=984). Home addresses were obtained from electronic medical records and linked to collision site from the trauma registry. The distance from home address to collision site was defined as the shortest walking distance as determined by Mapquest (www.mapquest.com). Home address census tract and census tract poverty rate were determined using the US Census Bureau's Factfinder (www.census.gov). Regression analysis was employed to assess patterns in distance from home to collision sites. Group means and confidence intervals were reported, and t-tests were employed to compare groups. From 2005-2009 (inclusive) 984 patients presented as pedestrians struck in ped-auto collisions. After elimination of patients without complete home or collision addresses, 616 patients were available for distance analysis. Analysis found 438/616 (71%) patients were struck within 4 miles (mi) of their home addresses. The number of pedestrians struck had a strong negative relationship to distance from home (r = −0.921, p<0.00). Pedestrians aged 0-14 y and pedestrians aged >65 y were struck, on average, closer to home at 3.1 mi (CI 1.9 - 4.3) and 1.5 mi (CI 1.0 - 2.0), respectively, in comparison to other age groups 15-24 (6.1, CI 4.2-8.0), 25-44 (7.0, CI 5.8 - 8.2), 45-64 (5.8, CI 5.0-6.6). Sixty-two percent of pedestrians were male. Average ISS scores of individuals struck >4mi from home and individuals struck <4mi from home were similar (p = 0.07). Sixty-five percent of these pedestrians resided in census tracts with poverty rates higher than the county-wide average of 9.9%. The average distance from home in those from census tracts >9.9% poverty rate was significantly closer (p = 0.03) at 4.1 mi versus 5.7 mi in those from census tracts with <9.9% poverty rate. The majority of these ped-auto victims were male and were within 4 mi of their home. Those aged <14 yrs and >65 years were struck closer to home than other age groups. Individuals residing in census tracts with higher than the county average poverty rate (9.9%) were more prevalent in our population and were struck closer to home that those residing in census tracts with lower than average poverty rates. These results provide suggestion for further exploring the roles of extremes of age and poverty as factors influencing pedestrian injury close to home.