A Novel Method for Verifying War Mortality while Estimating Iraqi Deaths for the Iran-Iraq War through Operation Desert Storm (1980-1993)

<div><p>Objectives</p><p>We estimated war-related Iraqi mortality for the period 1980 through 1993.</p><p>Method</p><p>To test our hypothesis that deaths reported by siblings (even dating back several decades) would correspond with war events, we compared sibling mortality reports with the frequency of independent news reports about violent historic events. We used data from a survey of 4,287 adults in 2000 Iraqi households conducted in 2011. Interviewees reported on the status of their 24,759 siblings. Death rates were applied to population estimates, 1980 to 1993. News report data came from the ProQuest <i>New York Times</i> database.</p><p>Results</p><p>About half of sibling-reported deaths across the study period were attributed to direct war-related injuries. The Iran-Iraq war led to nearly 200,000 adult deaths, and the 1990–1991 First Gulf War generated another approximately 40,000 deaths. Deaths during peace intervals before and after each war were significantly lower. We found a relationship between total sibling-reported deaths and the tally of war events across the period, p = 0.02.</p><p>Conclusions</p><p>We report a novel method to verify the reliability of epidemiological (household survey) estimates of direct war-related injury mortality dating back several decades.</p></div

Estimates of the probability of dying between age 15 and age 60, in Iraq 1979–1993.

<p><b>Source of data:</b> Survey of 4,287 adults in 1,960 households in Iraq between May and July of 2011, reporting on 782 sibling deaths by cause between 1980 and 1993. Data provided by the University Collaborative Iraq Mortality Study, which collected household and sibling data from 2000 households across Iraq in 2011. The blue points illustrate the estimation of the male 45q15, and the light blue shading illustrates the male 95% uncertainty intervals; The red points illustrate the estimate of female 45q15, and the light red shading illustrates the female uncertainty intervals.</p

Raw number of siblings death by year and cause, Iraq 1979–1993.

<p><b>Source of data:</b> Survey of 4,287 adults in 1,960 households in Iraq between May and July of 2011,782 sibling deaths by cause between 1980 and 1993. Data provided by the University Collaborative Iraq Mortality Study, which collected household and sibling data from 2000 households across Iraq in 2011. Direct war-related injury deaths / total deaths = 45.3%. Among other deaths, 23.1% were attributed to cardiovascular disease, 22.2% to other injury, 10.7% to cancer, 37.0% to “other” and 7.0% to “don’t know.”</p

Estimates of numbers of adult deaths per week in Iraq, 1979–1993, by cause as reported by siblings.

<p><b>Source of mortality data:</b> Survey of 4,287 adults in 1,960 households in Iraq between May and July of 2011, reporting on 782 sibling deaths between 1980 and 1993. Data provided by the University Collaborative Iraq Mortality Study, which collected household and sibling data from 2000 households across Iraq in 2011; Event calendar collected from literature review. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164709#pone.0164709.ref024" target="_blank">24</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164709#pone.0164709.ref027" target="_blank">27</a>]</p

Correlation between reported total Iraqi sibling deaths and new-reported war events, 1980–1993.

<p><b>Source of data:</b> Deaths come from a survey of 4,287 adults in 1,960 households in Iraq between May and July of 2011, reporting on 782 sibling deaths by cause between 1980 and 1993. Data provided by the University Collaborative Iraq Mortality Study, which collected household and sibling data from 2000 households across Iraq in 2011. Total incidents come from our review of ProQuest Historical Newspapers database for <i>New York Times</i> articles about Iran or Iraq for the period 1980–1993, illustrating 4,769 non-duplicate events. Spearman correlation between war events and total sibling-estimated deaths is 0.60, <i>P-value</i> 0.02 (note: sensitivity analysis removing strong upper right hand data point, associated with Desert Storm, reduces certainty to p-value 0.07). Spearman correlation between war events and violent war deaths is 0.51, <i>P-value</i> 0.06. Spearman correlation between war events and deaths not associated with war is 0.41, <i>P-value</i> 0.14.</p

Sample size and counts of siblings in Iraq, by governorate.

<p>Sample size and counts of siblings in Iraq, by governorate.</p

Density of civilian deaths in Baghdad, with the cluster locations of the University Collaborative Iraq Mortality Study as well as 2006 cluster locations of a previous study [30].

<p>The density map was generated using a kernel density estimation of civilian deaths from the Wikileaks Iraq War Logs release <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001533#pmed.1001533-The1" target="_blank">[55]</a>. The kernel density estimation provides a smoothed surface from a point pattern that represents spatial variation in the density of events, in this case civilian deaths. This allows for a crude visual analysis of the variation of events across space in Baghdad as well as the relation of 2006 and 2011 cluster locations to the density of civilian deaths. Analysis is based on geolocated data of all civilian deaths by any means reported in the Wikileaks Iraq War Logs data from 2004 to 2009.</p

Sample size and counts of household members and siblings in the University Collaborative Iraq Mortality Study, by governorate.

<p>Population data from COSIT.</p>a<p>As a check of validity.</p

Estimates of numbers of adult deaths per week in Iraq for 2-y intervals, 2001–2011, by cause as reported by siblings in the University Collaborative Iraq Mortality Study.

<p>National estimate of deaths in Iraq between 2001 and 2011. Age-specific mortality rates were estimated separately within 2-y blocks (the first two time intervals are not strictly 2 y long, in order to align the first interval dividing point with the start of the war in March 2003; the survey concluded July 2, 2011, so the final bar reflects only half of the year). The counterfactual (had there been no war) estimate shows the predicted death counts if crude death rates had remained at their average level from 2001–2002 during the war and occupation (in gray). War-related, but not violent, deaths above the normal baseline are in the salmon-colored area. War-related violent deaths are portrayed in red. The estimates use the ICSS method to correct for survival bias <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001533#pmed.1001533-LevinRector1" target="_blank">[33]</a>.</p

Raw number of adult deaths by year and cause, 2001–2011, reported by the University Collaborative Iraq Mortality Study.

<p>Counts of deaths reported by respondents to the sibling survival questionnaire, by year and cause. The estimates use the ICSS method to correct for survival bias <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001533#pmed.1001533-LevinRector1" target="_blank">[33]</a>. The survey concluded July 2, 2011, so the final bar reflects data for only half of the year.</p