Research In Action

What They Did

In this population-based retrospective analysis of MVC-related deaths in children (<15 years) from 2014-2018, MVC deaths in children who were occupants of passenger vehicles were derived from the Fatality Analysis Reporting System of the National Highway Traffic Safety Administration, a population-based registry that collects data related to every MVC in the US that results in at least 1 fatality within 30 days.

Specifically, the study examined the association between the county rate of pediatric MVC mortality (deaths per 100,000 child-years) and the highest level of pediatric trauma care present within each county, categorized as:

• pediatric trauma center
• adult trauma center (level 1 or 2)
• adult trauma center (level 3)
• no trauma center

Analysis was adjusted for the following factors that might also influence MVC mortality rate:

• county rurality (measured using population density and rural-urban continuum codes, with counties grouped into quartiles)
• access to pre-hospital care (i.e., ground emergency medical service response times and the availability of emergency medical service helicopters)
• state traffic laws (i.e., speed limits on highways)

What They Found

• During the 5-year study period, there were 3,067 pediatric MVC-related deaths.
• The least densely-populated regions were associated with the highest pediatric MVC mortality (8.2 deaths per 100,000 child-years) compared to 0.56 deaths per 100,000 child-years in the most densely populated counties.
• Nearly 33% of the most densely populated regions contained pediatric trauma centers, whereas 99% of the least densely populated counties contained no trauma center.
• Median distance to a pediatric trauma center was 23 km for the most densely populated regions, compared to 297 km for the least densely populated regions.

After adjusting for other variables that might influence MVC mortaliy rate (rurality, access to pre-hospital care, and state traffic laws), compared to counties with no trauma center:

• Counties with pediatric trauma centers had significantly lower rates of MVC mortality in children (MRR, 0.58; 95% CI, 0.39–0.86).
• Similar findings were seen in counties with level 1 or 2 adult trauma centers (MRR, 0.65; 95% CI, 0.47–0.89).
• There was no reduction in MVC mortality rates in children in counties with adult level 3 trauma centers.
• Greater mortality was associated with lower population density and higher maximum speed limits on rural highways.
• The presence of a non-trauma center children’s hospital did not change the significant reduction in risk of pediatric MVC mortality in counties with pediatric or level 1 or 2 adult trauma centers.

Of the variation in state-based pediatric MVC mortality:

• Nearly 10% was attributable to county differences in access to care.
• 53% was attributable to measures of rurality.

What This Means

Some important limitations include the fact that certain variables, such as vehicle miles driven, or regional differences in driving behaviors, could not be measured in this dataset and may impact MVC-related mortality risk (though these factors correlate with rurality, which was accounted for in the analysis). In addition, variables such as access to care were not measured on an individual level, impacting the ability to interpret these results at an individual level.

This study identified disparities in access to pediatric trauma care by region and population density and found that these disparities do impact MVC-related pediatric mortality risk. The study also begins to identify targets for improvement, as variation in state level MVC-related mortality was partly attributable to county differences in access to care. Another significant source of variation in state trauma system performance was degree of rurality; more research is needed to examine factors that contribute to MVC differences between rural and urban regions.