STRUCTURED ABSTRACT
Objective
The study was conducted to determine the association between vehicle-, crash- and demographic-related factors and injuries to front seat far-side occupants in modern environments.
Methods
Field data were obtained from the United States (US) National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) database, for the years 2009–2012. Inclusion factors: adult restrained front outboard seated occupants, no ejection or rollovers, and vehicle model years less than 10 years old at the time of crash. Far-side crashes were determined by using collision deformation classification. Injuries were scored using the Abbreviated Injury Scale (AIS). Injuries (MAIS2+, MAIS3+, M denotes maximum score) were examined based on demographics, change in velocity, vehicle type, direction of force, extent zone, collision partner and presence of another occupant in the front seat. Only weighted data were used in the analysis. Injuries to the head and face, thorax, abdomen, pelvis, upper extremity and lower extremity regions were studied. Odds ratios and upper and lower confidence intervals were estimated from multivariate analysis.
Results
Out of 519,195 far-side occupants, 17,715 were MAIS2+ and 4,387 were MAIS3+ level injured occupants. The mean age, stature, total body mass, and BMI were 40.7 years, 1.7 m, 77.2 kg, and 26.8 kg/m2, respectively. Of occupants with MAIS2+ injuries, 51% had head and 19% had thorax injuries. Of occupants with MAIS 3+ injuries, 50% had head and 69% had thorax injuries. The cumulative distribution of changes in velocities at the 50th percent level for the struck vehicle for all occupants and, MAIS2+ and MAIS3+ occupants were 19, 34 and 42 km/h, respectively. Furthermore, 73% of MAIS2+ injuries and 86% of MAIS3+ injuries occurred at a change in velocity of 24 km/h or greater. Odds of sustaining MAIS2+ and MAIS3+ injuries increased with unit increase in change in velocity, stature and age, with one exception. Odds of sustaining injuries were higher with the presence of an occupant in the front seat at the MAIS3+ level, although it was reversed at the lower level. The extent zone of 3+ increased the odds compared to the extent zones of 1 to 2 at both MAIS2+ and MAIS3+ injuries. Odds ratios and confidence interval are given.
Conclusions
Findings that head and thorax are more frequently injured body regions, prevalence of cranium injuries are similar at both injury severities; thoracic injuries are more prevalent at the MAIS3+ level; presence of another front seat occupant plays a role in MAIS3+ trauma; injuries continue to occur at change in velocities representative of side impact environments; mean demographic factors are close to mid-size automotive anthropometry, indicate the need to pursue this line of study. Because data were gathered from only four years, it would be important to include additional NASS-CDS database years, rescore injuries from previous years and/or analyze other international databases to reinforce these findings for advancing safety ...
