Using data from two surveys, the researchers estimated 405,000 people were killed and projected 55,800 more deaths from migration into and emigration from Iraq because of the war, al-Jazeera America reported Wednesday.
The study, released Tuesday and published in PLoS Medicine, included a survey of 2,000 Iraqi households in 100 geographic regions in Iraq. Researchers used two surveys -- one involving the household and one asking residents about their siblings to try to demonstrate the accuracy of the data collected.
The researchers estimated 60 percent of the deaths were violent and 40 percent occurred because of health infrastructure issues that were present because of the U.S. invasion. She said about half of the non-violent deaths were attributed to inadequate treatment for cardiovascular disease.
"I hope that one of the takeaways from this paper will be that when we invade a country, there are many health consequences that aren't directly related to violence," said study author Amy Hagopian, program director of the community-oriented public-health practice at the University of Washington School of Public Health.
While the decision to go to war in Iraq and its consequences will remain subject to debate, the study's editor said the emphasis should shift to how to lessen the war's toll going forward.
"We'll never know the true number of people who died as a result of the war," said Edward Mills, Canada research chair in global health at the University of Ottawa. "You just can't come up with a number that's going to be the absolute number."
He said the focus now should be on rebuilding Iraq and called on countries not involved in the war to participate in the rebuilding.
"I think that the period of contention is over, and the focus now should not be on putting the blame on anyone," he said, "but on how do we figure out rebuilding the health structure in this environment."
The latest study may negate some of the criticism leveled against previous studies on Iraqi death rates after the invasion published in The Lancet in 2004 and 2006, al-Jazeera America said. The 2006 study in particular was a subject of scrutiny because it estimated a toll of 655,000 deaths, mostly violent, when other surveys had five-digit numbers. Much of the criticism focused on methods in the study that could have been improved and would have produced more accurate results.