Austin, Texas - More than two months after the Austin American-Statesman detailed how hundreds of Texas veterans of Iraq and Afghanistan have died since coming home - and the government's failure to adequately track them - the Department of Veterans Affairs said it will launch a mortality study that will seek similar information for veterans nationwide.

While the VA has periodically studied suicide among Iraq and Afghanistan veterans, it has done far less to understand other causes of death, including drug overdose. A six-month Statesman investigation found that nearly as many Texas veterans had died after taking prescription medicine as have committed suicide.

Using autopsy results, toxicology reports, inquests and accident reports from more than 50 agencies throughout the state, the Statesman determined the causes of death for 266 Texas veterans who served in operations Enduring Freedom and Iraqi Freedom and were receiving Department of Veterans Affairs disability benefits when they died. It was the first time a comprehensive view of how recent Texas veterans are dying has been produced.

The Statesman investigation found that the VA doesn't track individual causes of death for the veterans it serves, and until now, hasn't publicly released a comprehensive breakdown of causes of death. Critics said the shortcoming prevents the VA from understanding the full scope of the problems facing those who fought over the past decade.

After the Statesman's report, state and federal lawmakers called on the VA to improve its data collection and provide fuller information to the American public. U.S. Rep. Bill Flores, R-Texas, said he would push for congressional hearings on the VA's data limitations.

VA officials told the Statesman that its Office of Public Health Post-Deployment Epidemiology Program would review "the universe of causes, including drug overdose and motor vehicle crashes." The study will be based on a roster of veterans who were deployed to a combat theater, provided by the Defense Department, that will be matched up to causes of death listed on death certificates and compiled by the federal Centers for Disease Control and Prevention's National Death Index.

The study could serve as a foundation, on a national scale, for evaluating services that veterans currently receive. VA officials wouldn't respond to questions about how the study will be used.

While the VA wouldn't say how it would use or publicize the results, former VA researcher B. Christopher Frueh, a post-traumatic stress disorder expert at the Menninger Clinic in Houston, said the study appears promising.

"If they do it well, they should be able to answer the questions people are asking: How many veterans are dying and what are they dying from?" he said. "This actually could be really good stuff, even if they replicate what (the Statesman) did on a national level."

In 2008, the department ran its list of Afghanistan and Iraq veterans in the VA system through the CDC index in order to study suicides, but it hasn't publicly released a comprehensive breakdown of causes of death.

The VA emphasized that death certificate causes might not always be reliable. Death certificates often underreport suicides and drug overdoses, experts say.

A more thorough reporting system, the CDC's National Violent Death Reporting System, can better identify veterans who die from suicide or other violent causes, but as only 18 states currently make reports to the system. The CDC estimates that expanding to all 50 states would cost $25 million, which Congress hasn't yet appropriated.

The Statesman investigation, which relied on 345 fragmentary death records provided by the VA - as well as obituaries and interviews with veterans' families - revealed disturbing patterns of early death among veterans who have returned home after deployments to the war zone. Of the veterans on the list, more than 1 in 3 died from a drug overdose, a fatal combination of drugs or suicide, and nearly 1 in 5 died in a motor vehicle crash.

Of those with a primary diagnosis of post-traumatic stress disorder, the numbers are even grimmer: 80 percent died of overdose, suicide or a single-vehicle crash. Only two of the 46 Texas veterans of the Iraq and Afghanistan operations who had a PTSD diagnosis died of disease or illness, according to the newspaper's analysis.

The investigation also found that VA prescriptions for powerful narcotics have skyrocketed over the past decade even as evidence mounted that such painkillers and PTSD make a dangerous combination.

In effect, experts said, the military and VA exposed an especially vulnerable population to a flood of powerful drugs.

VA officials said that, because they don't have access to all individual causes of death, they couldn't verify the newspaper's numbers or determine if they mirror causes of death for young veterans nationally. That information gap could conceivably be remedied by the upcoming mortality study.

However, no governmental entity follows the fates of the hundreds of thousands of veterans who aren't enrolled with the VA - nearly half of all recent veterans.

Throughout the current conflicts, critics have accused the VA of being slow to study and acknowledge the deaths of the veterans it serves. In 2008, a CBS News investigation revealed an "alarming" rate of suicide among veterans and a failure by the VA to gather the nationwide data needed to track the deaths.

Six months later, the U.S. House Committee on Veterans' Affairs blasted the agency for "denying" and "underplaying" suicides after emails surfaced that showed VA officials sought to keep the numbers of suicides and suicide attempts - the latter totaling 950 per month among VA patients - from public view. In the aftermath, lawmakers ordered the VA to do a better job of tracking and reporting veteran suicides.

VA officials say they are hopeful that better cooperation with the Defense Department and individual states will help them better study the fates of the nation's veterans. The VA is pushing all 50 states to improve reporting of veterans' deaths by making it clear if the deceased is active duty or has left the military (currently, most states make no distinction).

And perhaps most important, the Defense Department is in the midst of a years-long process of merging medical records with the VA, which VA officials say will give them the capability to track veterans outside of its system as well.