Wrong - The study calculates excess deaths FROM ALL CAUSES postwar as opposed to prewar. The 95% Confidence Intervals is wide, from 8,000 to 194,000. Luckily we are starting to get larger sample studies with smaller CIs, such as Iraq Living Quality Study - which largely vindicate the lancet study.
Needless
> to say, this study will become an article of faith in certain circles
> but the study is obviously bogus on its face.
>
> First, even without reading the study, alarm bells should go off. The
> study purports to show civilian casualties 5 to 6 times higher than
> any other reputable source. Most other sources put total combined
> civilian and military deaths from all causes at between 15,000 to
> 20,000. The Lancet study is a degree of magnitude higher. Why the
> difference?
>
What source is this? If its from Iraq body count (that has numbers in that range) then that would be a study of violent deaths - not deaths from all sources. The Iraq Living Quality Survey http://www.iq.undp.org/ILCS/overview.htm has recently been touted as disproving the Lancet study because it only shows 24,000 violent deaths from warfare. The Lancet study number of deaths from war violence is 33,000 - however the lancet study covered 18 months after the invasion while the ILQS covered only one year after the war - the month average death by war is similar but slightly higher the much larger ILQS study.
> Moreover, just rough calculations should call the figure into doubt.
> 100,000 deaths over roughly a year and a half equates to 183 deaths
> per day. Seen anything like that on the news? With that many people
> dying from air strikes every day we would expect to have at least one
> or two incidents where several hundred or even thousands of people
> died. Heard of anything like that? In fact, heard of any air strikes
> at all where more than a couple of dozen people died total?
>
Again - the Lancet study covers all causes of deaths not just war related violence - Comparing the the lancet study numbers to Iraq Body Count one can have a rough estimate that roughly one out of three deaths are not reported in the media - a not so unlikely proposition.
> Where did this suspicious number come from? Bad methodology.
>
>From the leading figures in the field of epidemiology. For example the
Chronicle of higher education
(http://chronicle.com/free/2005/01/2005012701n.htm) notes
"Les has used, and consistently uses, the best possible methodology," says Bradley A. Woodruff, a medical epidemiologist at the U.S. Centers for Disease Control and Prevention.
Indeed, the United Nations and the State Department have cited mortality numbers compiled by Mr. Roberts on previous conflicts as fact -- and have acted on those results.
> >From the summary:
>
> Mistake One:
>
> "A cluster sample survey was undertaken throughout Iraq during September, 2004"
>
> It is bad practice to use a cluster sample for a distribution known to
> be highly asymmetrical. Since all sources agree that violence in Iraq
> is highly geographically concentrated, this means a cluster sample has
> a very high chance of exaggerating the number of deaths. If one or two
> of your clusters just happen to fall in a contended area it will skew
> everything. n fact, the study inadvertently suggests that this
> happened when it points out later that:
>
> "Violent deaths were widespread, reported in 15 of 33 clusters..."
>
> In fact, this suggest that violent deaths were not "widespread" as 18
> of the 33 clusters reported zero deaths. if 54% of the clusters had no
> deaths then all the other deaths occurred in 46% of the clusters. If
> the deaths in those clusters followed a standard distribution most of
> the deaths would have occurred in less than 15% of the total clusters.
>
> And bingo we see that:
>
> "Two-thirds of all violent deaths were reported in one cluster in the
> city of Falluja"
Falluja was considered an outlier and was exculded when deriving the
conclusions had they included it the final result would have been
higher. the Economist on this issue:
"The Fallujah data-point highlights how the variable distribution of
deaths in a war can make it difficult to make estimates. But Scott
Zeger, the head of the department of biostatistics at Johns Hopkins,
who performed the statistical analysis in the study, points out that
clustered sampling is the rule rather than the exception in
public-health studies, and that the patterns of deaths caused by
epidemics are also very variable by location."
http://www.economist.com/science/displayStory.cfm?story_id=3352814
>
> (They also used a secondary grouping system (page 2, paragraph 3) that
> would cause further skewing.)
>
> Mistake Two:
>
> "33 clusters of 30 households each were interviewed about household
> composition, births, and deaths since January, 2002."
>
> Self-reporting in third-world countries is notoriously unreliable. In
> the guts of the paper (page 3, paragraph 2) they say they tried to get
> death certificates for at least two deaths for each cluster but they
> never say how many of the deaths, if any, they actually verified. It
> is probable that many of the deaths, especially the oddly high number
> of a deaths of children by violence, never actually occurred.
They state that they got 81% of the death certificates they asked for,
those who didn't have them had believable reasons why, and the
interviewers were asked to judge if they thought the person was lying
- which they didn't find any.
>
> So we have a sampling method that fails for diverse distributions, at
> least one tremendously skewed cluster and unverified reports of
> deaths.
>
> Looking at the raw data they provide doesn't inspire any confidence
> whatsoever. Table 2 (page 4) shows the actual number of deaths
> reported. The study recorded 142 post-invasion deaths total with with
> 73 (51%) due to violence. Of those 73 deaths from violence, 52
> occurred in Falluja. That means that all the other 21 deaths occurred
> in one of the 14 clusters where somebody died, or 1.5 deaths per
> cluster. Given what we know of the actual combat I am betting that
> most of the deaths occurred in three or four clusters and the rest had
> 1 death each. Given the low numbers of samples, one or two fabricated
> reports of deaths could seriously warp the entire study.
>
> At the very end of the paper (page 7, paragraph 1) they concede that:
>
> "We suspect that a random sample of 33 Iraqi locations is likely to
> encounter one or a couple of particularly devastated areas.
> Nonetheless, since 52 of 73 (71%) violent deaths and 53 of 142 (37%)
> deaths during the conflict occurred in one cluster, it is possible
> that by extraordinary chance, the survey mortality estimate has been
> skewed upward. "
How many times do we need to remind that Falluja was an excluded outlier!
>
> Gee, you think? It's almost as if military violence is not randomly
> distributed across the population of Iraq but is instead intelligently
> directed at specific areas, rendering a statistical extrapolation of
> deaths totally useless.
>
> In the next paragraph they admit:
>
> "Removing half the increase in infant deaths and the Falluja data
> still produces a 37% increase in estimated mortality."
>
Again! How many times do we need to remind that Falluja was an excluded outlier!
In short this review cherry picks quotes to distort what the lancet study said. Of course the wide confidence Interval makes larger studies a neccessity, but lets not shoot the messenger.
-- Andy Barenberg
PS. More indepth discussion of the lancet study here: http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/science/LancetIraq/