Are the graphs misleading?
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|Thu, 05-08-2008 - 11:11am|
I am going to post a few exceprts from a web site that is trying to dispell anti-vaccination arguments.
Anti-vaccination sites almost all use graphs to delineate the myth that VPDs fell prior to the introduction of vaccines and that this serves as "proof" that vaccines were never the real reason for their decline. It's commonly held that improved living conditions, diet, and other medical intervention(s) resulted in the decline in VPDs and vaccinations had "nothing to do with it".
This view is partially correct in that the initial decline in VPD incidence and mortality were very much so related to improved hygiene, diet, and medical attention. However, vaccinations HAVE played an important role in the decline of VPDs and the use of these graphs on anti-vaccination websites is clearly deceiving.
An example is seen at the website of Sandy Mintz (http://www.vaccinationnews.com/diseases_and_vaccines/measles_deaths_graph.htm).
A cursory glance at this graph does show a nice decline in measles deaths prior to the introduction of measles vaccine. Couple interesting points about this information becomes apparent, though, when one closely examines the .pdf files under the graph. If you take the graph and blow it up between the years 1949 and 1984, you'll see a couple interesting things:
* The number of deaths were pretty steady for 13 YEARS before measles vaccine was introduced.
* Within 2 years after the introduction of measles vaccine, the number of deaths dropped suddenly from 300-600 deaths to less than 100 with the more recent number of deaths declining to less than TWELVE. (ZERO in 1998).
No doubt many of the measles deaths prior to the 1940's were related to hygiene issues, but the number of deaths PLATEAUED for over TEN years before the introduction of the vaccine and it is clear that the deaths from measles plummeted following the introduction of the vaccine. The Y- axis of the graph in the link is too broad to appreciate this decline.
Other graphs on anti-vaccination websites are similarly deceiving.
What do you think of this analysis?