Pedestrians injured by automobiles: Relationship of age to injury type and severity

Background There is little research on the effect of age on the nature and severity of injuries to pedestrians struck by automobiles. Study design Trauma registry study included all auto versus pedestrian trauma admissions of pedestrians injured by automobiles at an academic Level I trauma center over 10 years and 4 months. Injury Severity Score, severe body area (head, chest, abdomen, extremities) trauma with Abbreviated Injury Score >3, specific organ injuries, and mortality were calculated according to age groups (≤14 years, 15 to 55 years, 56 to 65 years, >65 years). Results During the study period 5,838 admissions were reviewed. There were 1,136 patients (19.4%) 14 years old or less, 3,741 (64.1%) who were 15 to 55 years, 420 (7.2%) 56 to 65 years, and 541 (9.3%) older than 65 years. Overall mortality was 7.7% and ranged from 3.2% in the age group 14 years or less to 25.1% in patients over 65 years. The incidences of severe trauma (Injury Severity Score >15) in the four age groups were 11.2%, 18.7%, 23.6%, and 36.8%, respectively. The incidences of critical trauma (Injury Severity Score >30) were 2.3%, 3.9%, 5.7%, and 13.9%, respectively. The incidence of severe head and chest trauma (Abbreviated Injury Score >3) increased with age. The incidence of solid organ and hollow viscus injuries was similar in all age groups. Spinal injuries increased significantly with age and ranged from 0.4% in the pediatric group to 8.5% in the elderly group. Pelvic and tibial fractures were significantly more common in adults; femur fractures were significantly more common in the pediatric group. Conclusions Age plays an important role in the anatomic distribution and severity of injuries and survival outcomes after pedestrian injuries.