Updated

Children are no safer riding in sport utility vehicles than in passenger cars, largely because the doubled risk of rollovers in SUVs cancels out the safety advantages of their greater size and weight, according to a study.

Researchers said the findings dispel the bigger-equals-safer myth that has helped fuel the growing popularity of SUVs among families. SUV registrations climbed 250 percent in the United States between 1995 and 2002.

"We're not saying they're worse or that they're terrible vehicles. We're challenging the conventional wisdom that everyone assumed they were better," said Dr. Dennis Durbin, a pediatric emergency physician who took part in the study, published Tuesday in the journal Pediatrics.

Eron Shosteck, a spokesman for the Alliance of Automobile Manufacturers, said he had not seen the study but cited government research released last summer that found SUVs have become less top-heavy since 2000 and made dramatic improvements in rollover resistance.

"SUVs have an exceptional safety record and are safer than or as safe as cars in the vast majority of crashes," Shosteck said.

The study, which Durbin called the first on SUVs and child safety, was sponsored by Partners for Child Passenger Safety, a research project of Children's Hospital of Philadelphia and the world's largest insurer, Bloomington-based State Farm Insurance Co.

The researchers looked at accidents involving nearly 4,000 children under age 16 between 2000 and 2003, and found child injury rates of about 1.7 percent in both cars and SUVs. The study examined only 1998 or newer cars and SUVs with second-generation air bags.

On average, the SUVs weighed 1,300 pounds more than the cars studied. The study found that the extra weight of SUVs enhanced safety, reducing the risk of injury by more than a third.

But that was offset by findings that SUVs were more than twice as likely as cars to roll over in crashes.

Children in rollovers were three times more likely to be seriously injured than those in non-rollover accidents, according to the study.

The findings surprised researchers, who assumed heavier SUVs were safer than cars when they launched the study a year ago, Durbin said.

SUV safety will probably improve because of legislation approved by Congress this year that requires the National Highway Transportation Safety Administration to develop standards for automakers to address SUV rollovers, he said.

"To the extent that SUV makers can solve the rollover problem, we may see them becoming the safe haven for children that they have the potential to be," Durbin said.

Automakers already have made strides through engineering and new technology such as electronic stability control, Shosteck said.

NHTSA spokesman Rae Tyson agreed but said he hopes the study will encourage families to check safety ratings closely before buying.

"I think there is a segment of the buying public that may be buying them with the false impression that they are buying the safest vehicle they can for their families," Tyson said.