WEDNESDAY, Oct. 6 (HealthDay News) -- Off-road motorcycles are safer than four-wheeled all-terrain vehicles (ATVs) in riding and racing crashes on trails, sand dunes and other rough terrain, a new, large-scale study shows.

In findings that may surprise racing enthusiasts and even safety experts, Johns Hopkins researchers found that victims of ATV crashes were 50 percent more likely to die of their off-road injuries than similarly injured motorcyclists.

In addition, ATV riders were 55 percent more likely to be admitted to an intensive care unit and 42 percent more likely to be placed on a ventilator.

The findings emerged from Johns Hopkins researchers' review of data on 60,000 patients who were injured in an off-road motorcycle or ATV crash between 2002 and 2006.

"There's a belief that four wheels must be safer than two," Cassandra Villegas, a researcher fellow at the Johns Hopkins Center for Surgery Trials and Outcomes, said in a Hopkins news release. "But we found the opposite. People involved in ATV crashes are more likely to die or suffer serious trauma."

The study was to be presented this week at a meeting of the American College of Surgeons in Washington D.C.

It's not clear why ATV crashes result in more severe injuries and increased risk of death, but the researchers suggested some possible factors. All-terrain vehicle riders may wear less protective clothing than off-road motorcyclists. Also, ATVs are much heavier than off-road motorcycles and can cause severe crush injuries when they land on top of crash victims.

The number of injuries in the United States involving ATVs or off-road motorcycles increased from 92,200 in 2000 to 150,900 in 2007, according to Villegas.

More information

The U.S. Consumer Product Safety Commission offers ATV safety tips.