Prison life may be dangerous, but getting out can be deadly, too. Newly released inmates were almost 13 times more likely than the general public to die during their first two weeks of freedom, a study in Washington state found.

Drug overdoses were the top killer, with ex-convicts 129 times more likely to die that way within two weeks of their release than the general population. That cause of death was followed by heart disease, homicide and suicide, according to the study, the first major look at the issue.

Over an average of two years, the study found the ex-inmates were 3 1/2 times more likely than other state residents and nearly four times more likely than current inmates to die.

“The differences are more striking for women then they are for men,” said lead researcher Dr. Ingrid Binswanger, a public health researcher and assistant professor at University of Colorado at Denver.

While 87 percent of ex-prisoners in the study were men, the risk of death for the women was 5 1/2 times higher than for other women in the state.

Experts said the rest of the country likely has a similar, or even worse, situation than Washington state, although the specific drugs causing overdoses might vary by region.

Binswanger, who did her research with colleagues while at the University of Washington, noted studies in Europe and Australia found similarly high death rates, particularly right after release from prison.

The new findings show the need for more programs to help ex-inmates with a history of addiction and poor health cope with the stress of finding housing, a job, health care and other necessities and stay clean, said Christy Visher of the Justice Policy Center at the Urban Institute.

Other experts said the results don’t surprise them, because inmates have far more physical and mental health problems than other citizens, often get inadequate treatment behind bars and get little help making the huge transition to society after a highly structured life.

“People need much more than a job and a place to put their heads,” said Nancy Wolff, who heads Rutgers University’s Center for Mental Health and Criminal Justice Research and is developing a curriculum for prisons to train inmates before release.

Binswanger’s study was reported in today’s New England Journal of Medicine.

It included 26,270 men and 3,967 women released from Washington state prisons from mid-1999 through 2003 and used two national databases to track their deaths. It compared them with deaths among other state residents of similar age, race and gender. Over that time, 443 inmates died, 38 in the first two weeks; an average of three deaths occurred among the same number of state residents over two weeks.

During the four-year study period, the highest number of deaths came from overdoses of alcohol and street and prescription drugs, 103; heart problems, 56; homicides, 54; suicides, 40; and cancer deaths, 39, many related to smoking, which was later banned in Washington prisons.

Ex-inmates were twice as likely as other citizens to die from heart disease, the country’s top killer, even though only 3 percent of the released prisoners were 55 or older.

The study was funded by the U.S. Department of Veterans Affairs and the Robert Wood Johnson Foundation of Plainsboro, N.J.