The Abbreviated Injury Scale (AIS) and the National Accident Sampling System (NASS) Occupant Injury Classification are widely used by automobile manufacturers, motor vehicle crash investigators, researchers and trauma centers. Updates of these systems in 1990 (AIS) and 1993 (NASS) hamper data collected in differing versions of these systems from being accurately combined or trended without severity adjustments. This paper discusses and summarizes major differences between these two coding systems, compares the number and percent distributions of injury by severity and reviews the need for methods to adjust severity. These differences in the two systems can lead to erroneous engineering conclusion that safety interventions has made a difference in injury severity when in fact the change is only an artifact of data merging using these different systems.
Samenvatting