A rough population study

... in The Lancet puts civilian deaths due to the March, 2003 invasion of Iraq at around 100,000. See Nature's story and the paper (PDF, requires free registration).

Findings The risk of death was estimated to be 2·5-fold (95% CI 1·6 4·2) higher after the invasion when compared with the preinvasion period. Two-thirds of all violent deaths were reported in one cluster in the city of Falluja. If we exclude the Falluja data, the risk of death is 1·5-fold (1·1 2·3) higher after the invasion. We estimate that 98 000 more deaths than expected (8000 194 000) happened after the invasion outside of Falluja and far more if the outlier Falluja cluster is included. The major causes of death before the invasion were myocardial infarction, cerebrovascular accidents, and other chronic disorders whereas after the invasion violence was the primary cause of death. Violent deaths were widespread, reported in 15 of 33 clusters, and were mainly attributed to coalition forces. Most individuals reportedly killed by coalition forces were women and children. The risk of death from violence in the period after the invasion was 58 times higher (95% CI 8·1 419) than in the period before the war.

Interpretation Making conservative assumptions, we think that about 100 000 excess deaths, or more have happened since the 2003 invasion of Iraq. Violence accounted for most of the excess deaths and air strikes from coalition forces accounted for most violent deaths. We have shown that collection of public-health information is possible even during periods of extreme violence. Our results need further veri cation and should lead to changes to reduce noncombatant deaths from air strikes.

-- Roberts et al, from the abstract