Hunold KM, Sochor MR, McLean SA, et al. Ambulance transport rates after motor vehicle collision for older vs. younger adults: A population-based study. Accid Anal Prev. 2014;73C:373–379.
How does epidemiology affect out of hospital care? Previous research has shown that patients over the age of 65 who aren’t transported by EMS have increased mortality. In this project published in Accident Analysis and Prevention, researchers reviewed data from the North Carolina Department of Motor Vehicles (DMV) looking at age, gender, ethnicity and transport rates after motor vehicle crashes (MVCs).
Data: DMV crash statistics from 2008–2011 showed 2,764,361 victims were registered in 1,113,958 crashes. Strictly looking at EMS arrival on scene and transport rates, multiple vehicle collisions were counted as one incident but each victim was accounted for. Records without a documented age, patients > 95 years of age, and cases where EMS wasn’t called were excluded, leaving 418,310 victims from 219,016 crashes. A total of 36.29% (175,768) patients were transported by ambulance. There was no difference in transport rates by age.
Of these crashes, 63.6% (139,294) occurred between two vehicles, 68% (148,931) occurred during the day and only 2.2% (4,818) involved drugs or alcohol.
Discussion: Both the 63% non-transport rate across all ages and the low percentage of alcohol involvement makes us wonder about the validity of this study’s methods. Data from this DMV database seems to account for crashes and people. The authors, however, don’t explain if having EMS on scene during incidents with multiple occupants meant everyone on that scene was injured or assessed when EMS arrived. These records included low-speed crashes—such as parking lot fender-benders—and EMS systems that may auto-start EMS on any possible collision regardless of injuries.
Previous research points to a 20–28% patient self-transport rate following evaluation by paramedics, but this database doesn’t indicate if those 242,542 patients refused care or self-transported.
So, what does this all mean? There’s great value in a study such as this one. We can look at the prevalence, location and severity of crashes, and make operational adjustments to deployment or potential bias (more Caucasian females appear to be transported).
The authors hypothesize that if EMS ensured all persons older than 65 were transported after a crash, North Carolina would have a three-fold increase in vehicular trauma transports (~7,000 more transports per year). They conclude this would be a costly and unacceptable solution in an already over-burdened EMS system.
Better criteria for determining who should be transported is needed.
We’d like to thank the authors for helping our understanding of injury patterns and age differences in care.
What we know: Elderly patients who aren’t transported have been shown to have worse outcomes.
What this study adds: The North Carolina DMV database transport rates are low across all age groups, including patients over the age of 65. More research is needed to determine if age, gender and ethnicity play a role in EMS non-transports.