SUNDAY, May 4, 2014 (HealthDay News) — Large numbers of U.S. high school students who are bullied take weapons to school, a new study finds.

“Victims of bullying who have been threatened, engaged in a fight, injured or had property stolen or damaged are much more likely to carry a gun or knife to school,” said study senior investigator Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at the Steven & Alexandra Cohen Children’s Medical Center of New York.

The researchers analyzed data from more than 15,000 U.S. high school students who took part in a 2011 survey. They found that teens who suffered many types of bullying are up to 31 times more likely to bring weapons such as guns and knives to school than those who have not been bullied.

The 20 percent of students who said they’d been bullied were more likely to be in lower grades, female and white, the researchers said. Almost 9 percent of them reported bringing weapons to school compared to less than 5 percent of kids who weren’t bullied.

Those more likely to admit “packing” for school said they had missed school because they felt unsafe either there or on the way to school; had property stolen or damaged; had been threatened or injured with a weapon; or had been in a physical fight.

Up to 28 percent of students who reported one of those factors took a weapon to school, and almost two-thirds of students with more than one of those factors did so.

The study was was to be presented Sunday at the Pediatric Academic Societies’ annual meeting in Vancouver, Canada.

“Tragedies like the Columbine High School massacre have alerted educators and the public to the grave potential for premeditated violence not just by bullies, but by their victims as well,” Adesman said in an American Academy of Pediatrics news release. “Our analysis of data collected by the [Centers for Disease Control and Prevention] clearly identifies which victims of bullying are most likely to carry a gun or other weapon to school.”

Dr. Lana Schapiro, the study’s principal investigator, said greater efforts need to be expended on reducing all forms of bullying.

“With estimates of more than 200,000 victims of bullying carrying a weapon to high school, more effective prevention efforts and intervention strategies need to be identified,” Schapiro said in the news release. “The greatest focus should not just be on bullies, but on the victims of bullies most likely to carry a weapon and potentially use deadly force if threatened.”

Data and conclusions presented at meetings are typically considered preliminary until published in a peer-reviewed medical journal.

More information

The U.S. National Library of Medicine has more about bullying.