Risk of permanent medical impairment (RPMI) in road traffic accidents.

In addition to investigating risk of death due to road traffic injuries, there is a need to better describe the risk of serious consequences. This study assessed risk of permanent medical impairment based on road traffic injuries classified according to AIS-2005. Injured car occupants were followed for at least 5 years to assess permanent medical impairment. After an initial injury, the risk of permanent impairment was established for injuries to different body regions and AIS levels. Degree of impairment was assessed according to a manual used by all Swedish insurance companies. Those included in the study were 20,484 car occupants injured in crashes that occurred between 1995 and 2001. Three risk levels of sustaining a permanent medical impairment (RPMI) were made. It was concluded that almost 10% of all car occupants with AIS1 injuries sustained a permanent medical impairment. It is therefore important to include minor injuries leading to impairment when measuring loss of health due to road traffic crashes. Furthermore the highest risk of sustaining a permanent medical impairment from an AIS1 injury was associated with injuries to the cervical spine and upper and lower extremities. One third of AIS3 head and cervical spine injuries led to the highest RPMI level of impairment. Injuries to the thorax and abdomen gave the lowest risk of permanent medical impairment on all AIS levels and all impairment levels. The result can be used for road transport system strategies, and for making priority decisions in vehicle design.