Objective To determine the RR of the severe injury associated with light truck vehicle (LTV) versus passenger vehicle (PV) mismatch following motor vehicle collisions across the USA.

Methods This was a retrospective cohort study with the primary outcomes of Injury Severity Score (ISS) >8 and body region Abbreviated Injury Score (AIS) >2. The National Automotive Sampling System Crashworthiness Data System (NASS CDS) was searched for occupants in frontal and side impact crashes from 1993 to 2007. Occupants in PVs struck by LTVs were compared to PV occupants struck by another PV. Poisson regression was used to estimate the RR of severe injury after adjusting for driver age, driver gender, and change in velocity during the crash (∆v). Because 21% of cases were missing ∆v, multiple imputation was used to estimate the missing values. NASS CDS weights were used to estimate the risk of severe injury nationally.

Results PV occupants in front impact crashes with an LTV as the striking vehicle were at increased risk of severe injury compared to those struck by another PV (RR 1.37, 95% CI 1.09 to 1.73). A similar increase risk was observed in side impact crashes (RR 1.34, 95% CI 1.12 to 1.62). Increased risk of injury was also identified in several body regions.

Conclusions Motor vehicle mismatch crashes are associated with a significant increase in risk of severe injury for PV occupants in the USA. Addressing vehicle compatibility remains an important issue for occupant safety.