WASHINGTON — Homeless veterans spend more time on the street than their civilian counterparts and are more likely to develop serious mental health illnesses or physical problems as a result, according to new research.

The 100,000 Homes Campaign released its study of more than 23,000 homeless citizens on Tuesday, the same day a new Pew Research Center report showed dissatisfaction among wounded troops with their post-military care. More than half said the government does not provide enough assistance.

“The physical, emotional and economic toll of a serious service-related injury does not end when the service member leaves the military,” the Pew report states. “Years and even decades after they were discharged, veterans who were badly hurt while serving are significantly more likely to be in poor health and somewhat less likely to be employed.”

Neither report focused solely on Iraq and Afghanistan veterans, but both hint at the long-term struggles facing that population in the years to come. Defense Department officials estimate that more than 1 million current servicemembers will leave the military by 2016, putting new pressure on veterans support services.

For years, veterans advocates have known that those who served in the military are more likely to end up in desperate poverty than civilians.

But the new homelessness report, based on interviews with homeless people across the country, found that veterans are likely to stay in those impoverished conditions almost two years longer on average than civilians. Homeless veterans average almost six years on the streets, compared to four years for non-veterans.

The extra time takes an emotional and physical toll. Homeless veterans suffered kidney disease, liver disease, frostbite and mental health illnesses at higher rates than non-military, researchers found. For veterans who spend more than two years without a home, the rates jump even higher.

“This shows we’ve got to go out and find these veterans who aren’t coming in to the shelters, given how lethal homelessness can be,” said Becky Kanis, director of the 100,000 Homes Campaign. “Every day we can take off the process could save a veteran’s life.”

Veterans interviewed for the report said wait times for housing assistance programs can reach up to year.

In a statement, VA spokeswoman Michelle Hammond said identifying and reaching homeless veterans is the primary challenge for department assistance efforts, but officials have focused on those efforts in recent months.

The Pew Center’s survey of nearly 2,000 former servicemembers found deep concerns that government efforts to help veterans don’t go far enough. Roughly a third of healthy veterans and more than half of wounded veterans said they feel the government “has not given them enough help.”

That included criticism of the utility of VA programs, access to veterans hospitals, and the Defense Department’s commitment to treat lingering injuries related to military service.

In response, Hammond said the VA “is doing more for the seriously injured and wounded veterans and servicemembers than has been done in any previous conflict or war,” citing the addition of veterans health care liaisons at military treatment facilities and new care management teams at VA medical centers.

Despite their complaints, 99 percent of the wounded veterans surveyed by the center said they were proud of their service and would advise others to enlist.

VA statistics show that about 2.2 million veterans — roughly one in every 10 veterans in American today — have a service connected disability.

shanel@stripes.osd.mil

Twitter: @LeoShane