NEW YORK (Thomson Reuters Foundation) - More than 18 percent of female students at one U.S. university reported incidents of rape or attempted rape during their first year at the institution, according to a new study.
Sexual violence on U.S. campuses has reached "epidemic levels," the study's authors said, and interventions to reduce it were urgently needed.
The survey, published in the Journal of Adolescent Health, was based on questionnaires of 483 participants and counted students' self-reported incidents of both rape and attempted rape.
Researchers polled young women at an unnamed college in upstate New York, identified in the study only as a "large private university", four times over a year.
Over the first two semesters, more than 15 percent of the respondents disclosed a rape or attempted rape, the study found.
"If you swap in any other physically harmful and psychologically harmful event, a prevalence of 15 percent would be just unacceptably high," Kate Carey, professor of behavioral and social sciences at Brown University School of Public Health and lead author of the study, said in a statement.
"If, for instance, 15 percent of our young people were breaking their legs in their first year of school, we would expect that the community would do something to enhance the safety of the environment."
The study said that estimates that distinguish between incidents of "forcible rape" and rape that occurred when alcohol or other drugs are used suggested that so-called "incapacitated rape" is more prevalent than forcible.
During the first year of college, "people are usually moving away from home for the first time, they are experimenting with a lot of freedoms including the use of alcohol and other drugs and learning how to live by themselves," said Carey.
Researchers also looked back at past experiences of polled students and found that 37 percent of the women said they had experienced at least one rape or attempted rape between the age of 14 and the start of sophomore year, their second year of college.
The scale of the problem of on-campus sexual violence nationwide has proved hard to assess.
Researchers are struggling to gather complete and reliable data due to a number of factors such as victims' reluctance to report incidents and a varying perception of what constitutes sexual assault.
In 2014, a widely-cited report that one in five female students has been raped was both validated and challenged by two dueling surveys that used very different methodology, the Washington Post reported.
Reporting by Maria Caspani, Editing by Ros Russell