A similar survey to the Lancet was done just after the invasion and Saddam went into hiding. The people told the pollsters that 3M+ were killed by Saddam, not having anything to do with the Iran-Iraq war.
Nonetheless:
http://www.newscientist.com/article/dn13164-new-study-says-iraqi-death-toll-significantly-lower.html
The death toll in Iraq may be far lower than previously claimed, according to a team working for the Iraqi Ministry of Health.
The researchers estimate that the number of violent deaths in Iraq between the US-led invasion of March 2003 and the end of June 2006 to be between 104,000 and 223,000.
This loss of life is described as "massive", but is well below the figure of 600,000 violent deaths claimed by a team of Iraqi and US scientists in autumn 2006 (The Lancet, vol 368, p 1421).
The Lancet research, led by public health experts from Johns Hopkins University in Baltimore, Maryland, US, was hailed by opponents of the war as evidence of the huge human cost of the conflict, but attacked with equal force by supporters of the invasion. President George W Bush publicly dismissed the study on the day it was released.
Larger study
The methods used to produce the estimate have since come under intense scrutiny although many experts believe the research was as good as it could have been given the dangerous and unstable conditions within Iraq.
The latest study is, however, likely to increase doubts about the 600,000 figure, not least because the new survey is far larger.
http://www.nejm.org/doi/full/10.1056/NEJMsa0707782
BACKGROUND
Estimates of the death toll in Iraq from the time of the U.S.-led invasion in March 2003 until June 2006 have ranged from 47,668 (from the Iraq Body Count) to 601,027 (from a national survey). Results from the Iraq Family Health Survey (IFHS), which was conducted in 2006 and 2007, provide new evidence on mortality in Iraq.
Full Text of Background...
METHODS
The IFHS is a nationally representative survey of 9345 households that collected information on deaths in the household since June 2001. We used multiple methods for estimating the level of underreporting and compared reported rates of death with those from other sources.
Full Text of Methods...
RESULTS
Interviewers visited 89.4% of 1086 household clusters during the study period; the household response rate was 96.2%. From January 2002 through June 2006, there were 1325 reported deaths. After adjustment for missing clusters, the overall rate of death per 1000 person-years was 5.31 (95% confidence interval [CI], 4.89 to 5.77); the estimated rate of violence-related death was 1.09 (95% CI, 0.81 to 1.50). When underreporting was taken into account, the rate of violence-related death was estimated to be 1.67 (95% uncertainty range, 1.24 to 2.30). This rate translates into an estimated number of violent deaths of 151,000 (95% uncertainty range,
104,000 to 223,000) from March 2003 through June 2006.
http://legacy.signonsandiego.com/news/world/iraq/memorial/20031210-1116-iraq-executions.html
The bloodiest massacres of Saddam's 23-year presidency occurred in Iraq's Kurdish north and Shiite Muslim south, but the Gallup Baghdad Survey data indicates the brutality extended strongly into the capital as well.
The survey obtained Monday, which the polling firm planned to release on Tuesday, asked 1,178 Baghdad residents in August and September whether a member of their household had been executed by Saddam's regime. According to Gallup, 6.6 percent said yes.
The polling firm took metropolitan Baghdad's population – 6.39 million – and average household size – 6.9 people – to calculate that 61,000 people were executed during Saddam's rule. Past estimates were in the low tens of thousands. Most are believed to have been buried in mass graves.
The U.S.-led occupation authority in Iraq has said that at least 300,000 people are buried in mass graves in Iraq. Human rights officials put the number closer to 500,000, and some Iraqi political parties estimate more than 1 million were executed.