The Insurance Institute for Highway Safety (IIHS) is issuing a report that provides their assessment of vehicle seat belt fit when using a belt-positioning booster car seat (booster car seat) in a wide range of vehicle seat belt systems. The results are based on specific use criteria defined by the IIHS, lap and shoulder belt anchorage locations representing a wide range of vehicles and their own rating criteria established for the purpose of this evaluation.
Based on our initial review of the report, we have found it emphasizes and rates only belt fit without weighing the effectiveness of booster seats in protecting children in crashes. While this research may be insightful when working in the laboratory with a test dummy, it does not take into account and provide a fair evaluation of the real world conditions of securing a child in the rear seat of a vehicle.
The safety benefits of booster car seats in real world crashes are well documented. Booster car seats are regulated by design and testing requirements by the National Highway Traffic Safety Administration (NHTSA) to achieve optimum performance and this cannot be ignored. A change in belt fit must be evaluated for the overall effect on the performance of the booster car seat and optimized along with all of the other requirements.
Report Specifics:
• Some of the booster seats in this study have been given a “Not Recommended” rating for belt fit even though real world experience with all booster seats is that they are providing good protection in crashes.
• The report is not clear on the “No Rating” classification. For the boosters that received the “No Rating” classification in the report, it should be emphasized that in order to confirm belt fit, parents or caregivers need to check the belt fit for a child in the specific vehicle in which it will be used.
• Many of the “Unrated Seats” are backless booster seats, but the real world experience indicates that the benefits were not significantly different for children in either type backless or high back booster seats according to a main finding of a new analysis from the Children’s Hospital of Philadelphia. The findings are a result of analyzing insurance claim data from crashes in 16 states and the District of Columbia from 1998-2007 involving 6,591 crashes and booster seats like those that are included in the IIHS ratings.
• Real world experience has demonstrated the safety benefits of booster car seats and research like that conducted by IIHS can provide tools to evaluate and optimize already good performing designs. However the ranking of booster car seats and classifying some as “Not Recommended” based on minor belt position variations that are not realistic in day to day use of a booster car seat is not appropriate.
• A “Not Recommended” rating does not mean that the product is unsafe. Instead it indicates that the seat belt is not optimally positioned per the evaluation criteria established by IIHS. Basing the “Not Recommended” rating only on optimum belt fit and ignoring the positive crash protection afforded by boosters is very short sighted.
• A “Not Recommended” rating for booster seats that have demonstrated a very positive reduction in the risk of injury in real world crashes is counterproductive as it can lead to consumer confusion, loss of confidence in the product and ultimately a reduction in use rates.
JPMA and its members agree that the primary purpose of a belt positioning booster is to lift up and reposition a child so the vehicle seat belts fit better. Proper belt positioning places the lap belt low on the hips, touching the thighs and the shoulder belt centered on the chest and over the shoulder. A key aspect of providing this vehicle belt fit is to prevent submarining that can lead to abdominal injuries and spinal cord injury often referred to as “seat belt syndrome”. JPMA is not aware of any reports of abdominal injury in crashes in booster car seats, and no crash testing was conducted as part of the study to asses seat belt fit.
Additional Statistics
Real world experience has proven that current booster car seats in use, like those evaluated in the IIHS study, have reduced the risk of injury 59% and risk of death 28% compared to restraining children with vehicle seat belts without a booster car seat. A study conducted by the Partners for Child Passenger Safety (PCPS) published in the June 2003 issue of the Journal of the American Medical Association, provided real-world evidence of the safety benefits of belt-positioning booster seats compared with seat belts alone as well as demonstrating that proper positioning of the seat belt by booster seats virtually eliminates injuries associated with seat belt syndrome, including injuries to the abdomen and spine. On-going evaluations continue to demonstrate the positive effects of booster seats in crashes.
As seen with adults, the fit of a seat belt varies for the adult from vehicle to vehicle and vary in different seating positions within the same vehicle. Booster car seat manufacturers recognize that there is a wide variation in vehicle seats and seat belt systems that can affect the belt fit with the booster and the child. Not all combinations of vehicle seats, seat belts, booster car seats and children work to compliment each other providing proper seat belt fit for the child. Parents are also advised that if the vehicle seat belt does not properly fit the child to move the car seat to a different seating location or not to use the booster car seat with that particular vehicle.
JPMA and the car seat manufacturers urge IIHS to reassess the ratings published and balance them with real world experience, emphasize that booster car seats have proven to be effective, and work with the industry to further evaluate procedures they have developed.
Links:
http://www.jpma.org