An exhaustive government survey of rape and domestic violence released Wednesday affirms that sexual violence against women remains endemic in the United States and in some instances may be far more common than previously thought.

Nearly one in five women surveyed said she had been raped or had experienced an attempted rape at some point, and one in four reported being beaten by an intimate partner. One in six women has been stalked, according to the report.

"That almost one in five women have been raped in their lifetime is very striking and, I think, will be surprising to a lot of people," said Linda C. Degutis, director of the National Center for Injury Prevention and Control at the Centers for Disease Control and Prevention, which conducted the survey. "I don't think we've really known that it was this prevalent in the population."

The study, called the National Intimate Partner and Sexual Violence Survey, was begun in 2010 by the CDC with the support of the National Institute of Justice and the Department of Defense. The study, a continuing telephone survey of a nationally representative sample of 16,507 adults, defines "intimate partner" and 'sexual violence" broadly.

The surveyors elicited information on types of aggression not previously studied in national surveys, including sexual violence other than rape, psychological aggression, coercion, and control of reproductive and sexual health.

They also gathered information about the physical and mental health of violence survivors.

Sexual violence affects women disproportionately, the researchers found. One-third of women said they had been victims of a rape, beating or stalking, or a combination of assaults.

The researchers defined rape as completed forced penetration, forced penetration facilitated by drugs or alcohol, or attempted forced penetration. By that definition, 1 percent of women surveyed reported being raped in the previous year, a figure that suggests 1.3 million U.S. women annually may be victims of rape or attempted rape.

That figure is significantly higher than previous estimates. The Rape, Abuse and Incest National Network last year estimated that 272,350 Americans were victims of sexual violence. And only 84,767 assaults defined as forcible rapes were reported in 2010, according to national statistics from the FBI.

But men also reported being victimized in surprising numbers.

One in seven men has experienced severe violence at the hands of an intimate partner, the survey found, and one in 71 men — 1 percent to 2 percent — has been raped, many when they were younger than 11.