STATEMENT OF THE PROBLEM
Motor vehicle crashes are the number one cause of death in the United States in children aged 14 years and younger, the number two cause of death in toddlers, and the number one cause of death in the 5- to 14-year-old age group. Proper restraint use can reduce these injuries and fatalities as shown in the literature. However, according to SAFE KIDS study, >8% of children are incorrectly restrained.1 Legislative efforts have been directed at reduction of these numbers. Two means to this end are primary and secondary laws. A primary law allows motorists to be pulled over and cited if noted to be in violation of that law. A secondary law does not allow motorists to be stopped for violating that law but instead mandates that motorists be stopped and cited for another violation before dealing with the one in question. All 50 states and the District of Columbia2 have some form of child restraint laws; however, only half are primary and none have detention options. Data regarding adults show primary laws are more effective in increasing compliance.
Despite these efforts, passenger vehicle occupant deaths among children were only 16% lower in 2004 than in 1975.3 In 2004, 5 children died and 586 were injured each and every day in motor vehicle crashes in the United States. Of those killed, half were unrestrained. In 2005, 29% or almost one-third of children younger than 1 year who were killed in motor vehicle crashes were totally unrestrained. Fifty-six percent of children aged 9 years to 12 years who were killed in motor vehicle crashes the same year were also totally unrestrained.4
This is obviously a public health issue of the greatest magnitude. The safety of our children is paramount. Therefore, we, in the Child Passenger Safety Workgroup of the Eastern Association for Surgery of Trauma (EAST) Practice Management Guideline Committee, examined the literature concerning the following questions to be answered.
QUESTIONS TO BE ADDRESSED
- What is the effectiveness of child passenger restraints in reducing morbidity and mortality?
- What is the effectiveness of legislation in the reduction of injuries and/or mortality?
We conducted a Medline search for human, English language literature from 1980 to 2006 on child passenger restraints. Child passenger restraints as keyword only yielded four results. Using “protective devices” or “seat belts” and combining that with “infant” over similar dates and restrictions resulted in 491 references, with “toddler” resulted in 6 references, with “child” resulted in 827 references, and with “adolescent” resulted in 842 references. Studies from other countries that involved legislation were dropped due to issues of generalizability. Fifty-nine were deemed appropriate to answer the above questions, and 55 of these were available for review. Fourteen articles examined legislation, and 41 articles examined restraint effectiveness with relation to outcomes. We did not use technical reports or engineering literature, as we felt that these were not relevant to the endpoints of morbidity or mortality and many could not be subject to scientific review.
Three class II and 21 class III articles demonstrated reduction of injury and/or injury severity with restraint use in children. Two class II and 10 class III articles demonstrated reduction of mortality with automotive restraint use in children when compared with unrestrained children. The risks of injury follow a continuum, with unrestrained children faring worse in a crash than improperly restrained children faring worse than restrained. Unrestrained 0- to 4-year-old children had relative risks (RR) of 4.4 for broken bones, 2.7 for concussions, 2.5 for open wounds, and 2.5 for hospitalization5 when compared with restrained children. In children aged 2 years to 5 years, premature graduation of children to seat belts had a RR for injury of 2.5 compared with those still in child safety seats. The RR was 4.2 for head injury in this study. The RR of injury was higher for 2-years to 3-years-old children (4.0) than 4 years to 5 years olds (2.4).6 In children aged 4 years and above, restrained children fared better than unrestrained.7 Compared with children in proper restraints, unrestrained children had three times the risk of injury. Inappropriate restraints also increased the risk of injury, doubling that risk compared with appropriate restraints.8 One large retrospective study of 5,751 children showed that among those children aged from 0 to 4 years, 27% were unrestrained compared with 44% of children aged 5 years to 11 years and 52% of children aged 12 years to 14 years. In the same study, overall figures showed that 38% of children were optimally restrained and 34% suboptimally restrained. Those with restraint devices were 2.7 times more likely not to have a serious injury.9 Another study of 600 children showed that age-appropriate restrained children had a significant reduction in severe injuries in every anatomic site except the back. This study also showed a reduction in solid and hollow visceral injuries as well as mortality with age-appropriate restraints.10
Other studies corroborated this risk reduction for age-appropriate, optimal restraints with a three-fold decrease in significant intra-abdominal injury and a 28% reduction in mortality risk.11,12 Forward-facing restraint systems were found to reduce injury compared with seat belts in the 1 year to 4 years age range.13,14 Two-point restraints (lap belts only) are associated with increased spinal cord injury compared with three-point restraints.15 Facial fractures are increased in inappropriately restrained children when compared with appropriately restrained children, RR 1.6. The increase in facial fractures also holds for children who are seated in the front seat when compared with those in the rear seat position, RR 1.8.16 Suboptimal restraint use has an RR of hollow viscus injury of 4.4 compared with appropriate restraint use.17 Improper use is cited in a class II article comparing restrained to unrestrained children, showing that restrained children were less injured than unrestrained. Serious injuries in this study resulted from improper use, using seat belts at an inappropriate age, or unavoidable circumstances such as intrusion or being struck by nonstationary objects.18
Belt-positioning booster seats also reduce injury. Overall, children in belt positioning booster seats, aged 4 years to 8 years, exhibited a 58% reduction in injury compared with children of same age using seat belts only. Much of this reduction in risk results from high-back belt positioning seats that exhibited a 70% injury reduction risk compared with seat belts alone. Backless booster seats were found to be no different from seatbelts in risk.19 Previous data from 2003 showed similar results.20
Only one class III article showed an increase in head and cervical spine injuries with restraint devices in children 0 to 8 years of age compared with those from 9 years to 18 years.21 Many have explained this predisposition by the anatomic differences in the developing pediatric C-spine. However, their evaluation was limited in that they could not determine whether the restraints systems were used properly or were appropriate to the weight and age of these younger children. Only one class III article addressed cost and showed a decrease in healthcare costs in Arizona with use of child passenger restraints.22 There were not enough articles to develop a recommendation on this topic.
Seven class III articles supported rear seat position for children aged 12 years and younger. Risk of injury and/or mortality in the front seat was 40% to 70% higher than the rear seat.9,16,23–27 One article documented risk reductions for fatal injury with rear seat position of 41% from age 1 year to 4 years, 30% from age 5 year to 12 years, and 32% from age 13 years to 18 years. The center rear seat was the safest with a 9% to 24% risk reduction for fatal injury compared with the outboard seats. Risk reductions applied to all but rear impact collisions. Restraints also reduced fatal injury risk in this study as well.26
Seven studies, one class II and six class III, showed increased injuries and mortality from airbags in children aged up to 12 years.23–25,27–30 One class II study showed as high as 84% mortality for unrestrained children and 31% mortality for restrained children with airbag deployment.23 This was even higher for restrained infants who were at 254% increased risk of dying in the front seat with an airbag compared those without airbag. This was the only study not to find increased mortality in children aged 9 years to 12 years from airbags. Two class III articles suggested that second-generation airbags may result in less injury than first-generation airbags.25,28
Six articles, three class II and three class III, demonstrated increased (perceived or observed) compliance with child restraint use with legislation.31–36 Three studies showed a decrease in injury,31,37,38 and three showed a decrease in mortality33,37,38 with enactment of child restraint legislation. The magnitude of the decrease in injury and death ranged from 10% to 50%. Ages in the studies were not uniform and ranged from 0 to 15 years.
Level I Standards
- Child restraint and restraint systems reduce injury and injury severity in all ages reported and are recommended for use.
- The highest reductions come from age-appropriate, properly used restraints, as per the American Academy of Pediatrics guidelines on selection and use of car safety seats (Appendix).
Please note that these recommendations rose to Level I standards based on the preponderance of available literature, including well-done class II data that support the age-appropriate use of child restraints and restraint systems as successful in the reduction of morbidity and mortality.
Level II Guidelines
- Rear seat position reduces injury at all ages studied and is recommended especially for those aged 12 years or younger.
- Airbags can cause injury and/or death to children aged 12 years or younger and thus seating position with exposure to airbags should be avoided in that age range.
- Child restraint laws help to reduce injury and mortality and increase compliance with restraint use.
Child restraints are clearly effective in injury prevention and reduction of injury severity at all ages examined, particularly high-back belt positioning booster seats. Rear seat position is also effective, especially when used in conjunction with child restraints. Legislation is also effective in improving compliance and even reducing injury. There are some data showing that primary laws are the most effective form of legislation. Further research is required on the effectiveness of legislation on injury and mortality.
1. Safe Kids Worldwide. Car seats, booster and seat belt safety fact sheet 2009; 2009. Available at: http://www.safekids.org/our-work/research/fact-sheets/car-seats-booster-and-belt-safety-fact-sheet.html
. Accessed March 15, 2010.
2. Insurance Institute for Highway Safety. Child restraint/belt use laws, 1996–2010. Highway Loss Data Institute. Available at: http://www.iihs.org/laws/restraintoverview.aspx
. Accessed March 15, 2010.
3. Insurance Institute for Highway Safety. Insurance Institute for Highway Safety (IIHS) Fatality facts 2004: children; 2004. Available at: http://images.businessweek.com/autos/pdfs/children.pdf
. Accessed March 15, 2010.
4. Insurance Institute for Highway Safety. Fatality facts 2005: children. Highway Loss Data Institute; 2006. Available at: http://www.iihs.org/research/fatality_facts-2005/children.html
. Accessed March 15, 2010.
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