Scene mobility status as a predictor of injury severity and mortality due to vehicular crashes.

Background: To examine the association of scene mobility status (SMS) and injury severity and mortality among motor vehicular crash (MVC) victims.

Methods: Adult MVC victims transported to medical facilities between 1997 and 2008 and included in the National Automotive Sampling System were studied. SMS was classified as follows: "ejected," "self-exited," "exited with assistance," "removed from the vehicle with decreased mental status," "removed due to perceived serious injury," and "removed for other reasons." Associations of SMS with Injury Severity Score and death were studied with contingency tables and multiple logistic regression models.

Results: A total of 62,634 cases representing 13,699,294 (weighted) cases were analyzed. Two percent of the cases were ejected, 38% self-exited, 18% exited with assistance, 4% removed with decreased mental status, 14% removed due to perceived serious injury, 1% other reasons, and 25% unknown. Mortality was highest among those ejected (8.7%). Those who self-exited and exited with assistance experienced a mortality of 0.02%. Injury Severity Score >8 occurred in 51% of those ejected, 37% of those removed with decreased mental status, 21% of those removed due to perceived serious injury, 4% of those who self-exited, and 5% of those exited with assistance. Multiple logistic regression revealed that those ejected, removed due to a low mental status or suspected injury, experienced higher adjusted odds ratios of dying than those who self-exited (odds ratio of 266 [69->999], 235 [61-903], and 66 (19-227), respectively).

Conclusion: MVC occupants who "self-exited" or "exited with assistance" experienced a very low injury severity and mortality. Further efforts are needed to decrease the overtriaging of these patients.