In car crashes with pedestrians, age and zip code may predict extent of traumatic injuries
Adults often face more severe injuries than children, and injuries frequently occur in areas with high levels of disparity, two studies show
American College of Surgeons
Key Takeaways
While both adults and children are severely injured in pedestrian-motor vehicle collisions, adults often face more serious outcomes than children, according to a national analysis.
In another study, mapping the geographical location of injuries in Colorado revealed areas in Denver County most prone to accidents, which could help researchers target efforts to prevent future crashes.
CHICAGO — Pedestrian-motor vehicle accidents are a common cause of injury in both children and adults, accounting for one death every 64 minutes and injuring thousands every year. Two recent analyses reveal that while both adults and children suffer serious injuries in collisions, adults tend to experience more severe outcomes than children. Additionally, mapping the locations of these injuries can pinpoint where accidents occur most frequently, offering valuable insights for targeting prevention efforts effectively.
The research will be presented at the American College of Surgeons (ACS) Clinical Congress 2025 in Chicago, October 4-7.
Adults Are More Severely Injured Than Children in Pedestrian-Auto Collisions
According to a national analysis led by a team of researchers at Morristown Medical Center in Morristown, New Jersey, pedestrian-motor vehicle collisions commonly lead to serious injuries in both adults and children; however, adults often face more serious outcomes than children.
Based on data from the ACS Trauma Quality Improvement Program (TQIP), the researchers analyzed injury patterns using the Injury Severity Score (ISS), which measures the overall effect of injuries using a scale from 1-75. An ISS score above 25 indicates that multiple regions of the body were injured simultaneously, which may include broken bones and severe bleeding injuries affecting organs. The researchers analyzed the injury patterns of 760 children (ages 1 to 17) and 760 adults over 18 using 2022 TQIP data.
Key Findings
Life-threatening injuries in both adults and children: In pedestrian-motor vehicle accidents, the average ISS score was 28 for adults and 26.4 for patients under 18, suggesting severe injuries in both groups.
Adults face more severe injuries than children: Adults experienced higher rates of mortality (18.8% vs. 8.1%) and other complications, including deep vein thrombosis (3.8% vs. 1.3%), a condition that can cause life-threatening blood clots, and cardiac arrest (5.3% vs. 2.6%). Adults were also twice as likely to have an unplanned operation compared to children. These differences were statistically significant.
Children’s bodies may be more adept at recovering from injury: The authors hypothesize that children may have better outcomes due to their ability to maintain blood flow to their organs and compensate for blood loss following an injury.
“That children did significantly better than adults was slightly surprising, as we would have expected there to potentially be worse outcomes for children, but it highlights the resiliency of pediatric patients and their bodies’ natural ability to compensate for blood loss in certain contexts,” said Eric J. Charles, MD, PhD, a trauma and acute care surgeon at Morristown Medical Center and co-author of the research.
However, no matter the age of the patient, the authors emphasized that motor vehicle accidents involving pedestrians very often lead to serious injuries that can quickly become life-threatening.
“There is very seldom a pedestrian who gets struck by a motor vehicle and walks away with limited injuries. This patient population usually sustains significant injuries that are often life-altering,” Dr. Charles said. “The overarching take-home message is that anything and everything we can do from an injury prevention standpoint and as a community to decrease the likelihood of pedestrians being struck by motor vehicles will likely make a tremendous difference in the health and well-being of the community.”
The location of the accidents and conditions that may have contributed to the collisions could not be analyzed using TQIP data, potentially limiting some of the study’s broader implications, the authors said. Future research will evaluate ways to prevent accidents, including improved signage, lighting, and visibility at crosswalks.
Mapping Injury “Hotspots” in Colorado
To understand where motor vehicle-pedestrian accidents happened most frequently in Colorado, researchers from the University of Colorado School of Medicine in Aurora, Colorado, analyzed injury patterns using the Colorado Department of Transportation (CDOT) database and a process called geocoding, which maps the location of injuries to understand injury patterns in clusters.
“Pediatric trauma is something we can prevent with dedicated efforts. If we can identify the causes of these injuries, we can work together to advocate for changes in our communities that can help decrease the chances that a child is struck by a car,” said Shannon Acker, MD, FACS, senior author of the study and an associate professor of pediatric surgery and trauma medical director at Children’s Hospital Colorado, in Aurora, Colorado.
Dr. Acker added that the unique position of Children’s Hospital Colorado also inspired the research project, as the hospital, a Level I pediatric trauma center, treats patients across seven states in the region.
Reviewing data from 321 pediatric patients injured from 2016 to 2024, researchers compared the rate of motor vehicle-pedestrian injuries in areas with high socioeconomic deprivation to areas with low deprivation as defined by the Area Deprivation Index (ADI). The ADI is a nationally ranked measure of neighborhood-level socioeconomic disadvantage, calculated using the American Community Survey across income, education, employment, and housing conditions.
The researchers then mapped the location of these injuries alongside ADI data to visualize geographically, based on density patterns, where car crashes involving pedestrians occur most frequently.
Key Study Findings
Neighborhoods with high disparity levels at risk: Motor vehicle crashes involving pedestrians occur more frequently in neighborhoods with high levels of disparity as defined by the ADI. In a previous analysis of patients treated at Children’s Hospital Colorado, the researchers found that rates of auto-pedestrian injuries were about 5 times higher if a patient resided in the highest ADI quintile compared to a patient residing in the lowest quintile.
Two major hotspots identified: Through geocoding, the researchers identified two injury hotspots where most motor vehicle-pedestrian accidents occurred in Denver County: one at the northern edge of the county at the intersection of Federal Boulevard and Exposition Avenue and another at the southern edge of the county at the junction of Federal Boulevard and Jewell Avenue.
Shifting density patterns: The researchers noted reduced density patterns at the intersection of Federal Boulevard and Exposition Avenue from 2022 to 2024 when compared to 2016 to 2021, suggesting fewer accidents occurred at this intersection after 2021. The authors hypothesize that a median placed at the intersection may have helped reduce accidents.
Studying the pattern of hotspots over time can pinpoint which areas may benefit from traffic calming measures and where rates of injuries have improved or worsened, the authors noted.
“The patterns in this research may not reflect national patterns. However, the methodology used can be applied nationally to understand the unique context that is contributing to auto-pedestrian injury disparities in other cities and states,” said Emily K. Myers, MD, lead author of the study and a pediatric surgery critical care fellow at Children’s Hospital Colorado.
Study co-authors of the geocoding study are Kaci Pickett-Nairne, MS; Keren Eyal, MD, MPH; Marina Reppucci, MD; Kathleen Adelgais, MD, MPH/MSPH; Maria Mandt, MD; and Jose L. Diaz-Miron, MD, FACS. Researchers are from the University of Colorado and Northwell Health in New Hyde Park, New York. The study was funded by the Center for Children’s Surgery Ponzio Grant.
Study co-authors of the clinical outcomes of motor vehicle collisions study are Zoltan H. Nemeth, MD, PhD; Jana K. Elsawwah, BA; Louis T. DiFazio, Jr., MD, FACS; and Rolando H. Rolandelli, MD, FACS.
Disclosures: The authors have no disclosures to report.
Citations:
Myers E, et al. Geocoding and Geospatial Analysis to Identify High Disparity Neighborhoods with a High Frequency of Auto-Pedestrian Injury and Develop Targeted Injury Prevention Programs, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2025
Nemeth Z, et al. Clinical Outcomes of Pediatric Versus Adult Pedestrian Motor Vehicle Collisions, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2025
Note: This research was presented as an abstract at the ACS Clinical Congress Scientific Forum. Research abstracts presented at the ACS Clinical Congress Scientific Forum are reviewed and selected by a program committee but are not yet peer reviewed.
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Method of Research
Data/statistical analysis
Subject of Research
People
Over 40% of deceased drivers in motor vehicle crashes test positive for THC, study shows
Six-year analysis in a major Ohio county shows no change in THC positivity after legalization
Key Takeaways
In a review of 246 deceased drivers, 41.9% tested positive for active THC in their blood, with an average level of 30.7 ng/mL — far exceeding most state impairment limits.
The high rate of THC positivity remained consistent over six years and was unaffected by the state’s legalization of recreational cannabis during the study period.
Messaging around the dangers of smoking cannabis and driving needs to be stronger, authors argue.
CHICAGO — New study findings show that over 40% of drivers who died in motor vehicle collisions tested positive for active delta-9-tetrahydrocannabinol (THC) in their system, with average blood levels far exceeding those considered to cause impairment. The research highlights a significant and persistent public health risk that is unchanged by the legalization of recreational cannabis, the authors said.
The research will be presented at the American College of Surgeons (ACS) Clinical Congress 2025 in Chicago, October 4-7.
Researchers analyzed coroner records from Montgomery County in Ohio from January 2019 to September 2024, focusing on 246 deceased drivers who were tested for THC following a fatal crash. When autopsies are performed, drug screening is typically part of the process. The study period included the state’s legalization of recreational cannabis in 2023.
“I was surprised to see that level,” said lead author Akpofure P. Ekeh, MBBS, FACS, a professor of surgery at Wright State University in Dayton, Ohio. “An average level of 30.7 ng/mL generally means those people must have consumed marijuana at some time close to driving. This isn’t about residual use; it’s about recent consumption.”
Key Study Findings
High Prevalence: 103 drivers (41.9%) overall tested positive for THC, with yearly rates ranging from 25.7% to 48.9%.
No Effect from Legalization: The rate of drivers who tested positive for THC did not change significantly before or after legalization (42.1% vs. 45.2%), indicating that legal status did not influence the behavior of those who chose to drive after use.
Consistent Over Time: The high rate of THC positivity showed no significant change over the six-year study period.
The study notes that blood THC levels are typically drawn by the coroner within hours of death, providing an accurate snapshot of a driver’s state at the time of the crash. Most states that have set legal limits for driving range from 2 to 5 nanograms per milliliter (ng/mL) — a threshold the average level in this study (30.7 ng/mL) far exceeded.
“The messaging over the last few years has been just the push towards recreational legalization,” Dr. Ekeh noted. “The problem is that from a public health standpoint, there has not been enough emphasis on some of the downsides and the dangers that can occur. People should treat smoking marijuana just like they treat alcohol: don’t smoke and drive.”
Co-authors are Lois Nguapa, BS; Clara Mussin Phillips, BS; and Ann Cardosi, BS, MPH.
Disclosures: The authors have no relevant disclosures.
Citation: Ekeh A, et al. Cannabis Prevalence in Drivers Involved in Motor Vehicle Crash Fatalities over a 6-Year Period, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2025.
Note: This research was presented as an abstract at the ACS Clinical Congress Scientific Forum. Research abstracts presented at the ACS Clinical Congress Scientific Forum are reviewed and selected by a program committee but are not yet peer reviewed.
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