Booster-seat use linked to reduced risk of death in car crashes

Booster seats save lives, and so do state laws requiring young children to ride in them, according to a new study.

Booster seats are aimed at kids who are too big for traditional car seats but too small to be properly restrained by seat belts alone. The seats boost these kids up so that a car’s shoulder belt secures them in a safe way. But their use is far from widespread: Only 48% of 4- and 5-year-olds use them, along with 35% of 6- and 7-year-olds, according to a 2008 survey by the National Highway Traffic Safety Administration, or NHTSA.

Considering that car crashes are the No. 3 cause of death for children between the ages of 1 and 18, booster seats have the potential to save many lives. So researchers from Children’s Hospital Boston and the Micheli Center for Sports Injury Prevention in Boston examined NHTSA data on all car crashes in the U.S. between 1999 and 2009 in which someone died.

During that decade, 47 states and the District of Columbia passed laws on booster seat use (though the provisions of those laws varied quite a bit). In the years before those laws were passed, the fatality rate from car crashes among 4- and 5-year-olds was 5.7 deaths per 100,000 kids. In the years after the laws went into effect, the death rate dropped to 4.2 deaths per 100,000 kids.

The trend was similar for older children. Among 6-year-olds, the fatality rate dropped from 2.3 to 1.5 deaths per 100,000 kids, the researchers found. Passage of booster-seat laws did not translate into a statistically significant reduction in death rates for 7-year-olds, but in states that required those kids to use booster seats, the death rate for 7-year-olds fell faster after those laws went into effect than it did in the years before.

In another part of the analysis, the researchers compared the fatality rates in states with booster-seat laws to the fatality rates in states without them. They found that 4- and 5-year-olds living in states with booster-seat laws were 11% less likely to die in car crashes than their counterparts in other states. The laws were also linked to a 23% reduced risk of death for 6-year-olds and a 25% reduced risk of death for 7-year-olds.

The results were published online Monday by the journal Pediatrics. You can read the study online here.

There’s still plenty of room for improvement, the researchers wrote. More than half of the 4- to 7-year-olds who are involved in a fatal car crashes aren’t using a seat belt and booster seat correctly. This policy statement from the American Academy of Pediatrics recommends that kids use booster seats until they are at least 8 years old and are 4 feet, 9 inches tall. Here’s the law in California.

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