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Six essays which constitute a short primer on
epidemiology have been posted to the website of the People’s
Epidemiology Library, a joint project of Columbia University’s
Alfredo Morabia and Leiden University’s Jan Vandenbroucke
to bring together documents and essays about the development of
epidemiologic methods. These essays were commissioned to help
explain epidemiology for laypersons coming to the site for
resources. The essays are a work in progress
and both Morabia and
Vandenbroucke contributed to them.
The principal author of the essays is McMaster
University’s Stephen Walter who was selected for the task
in an essay competition run by the Library in 2011. Walter told
The Epidemiology Monitor, which helped to sponsor the contest,
that writing for the public was not something which academic
epidemiologists do very often but which he thought is important.
He said he would try to convey his enthusiasm for the discipline
and why epidemiology is so important in contemporary society.
The topics for the six essays along with selected
excerpts from each one are included below, along with links to the
essays. Some of the excerpts have links to references as well.
#1
Introduction to Epidemiology
For a sample of this essay, here is a how Walter
presents Snow for the lay public.
In London, some 200 years
after Graunt, the epidemiologist John Snow’s studies compared the
mortality from cholera between the clients of two companies
providing water in London.[Snow,
1855] The study confirmed his hypothesis that getting cholera
was somehow linked to contaminated drinking water. The specific
inquiry of a cluster of cases which occurred in the vicinity of
Broad Street famously led to the removal of the handle of the
Broad Street water pump. This was a controversial move at the
time, because several other theories about the cause of cholera
existed, including the notion that living at a low altitude would
increase the population’s exposure to dangerous vapours. We know
nowadays that Snow was right, and the provision of a clean and
secure drinking water supply was one of the main elements of a
major movement towards improving public health during the 19th
century and subsequent.[Vandenbroucke
et al, 1991]ly
http://tinyurl.com/adho779
#2
How to Count
For a sample of this essay, we have chosen Walter’s
paragraph on the distinction between risks and incidence rates
The formal distinction between risks and incidence rates goes back
to William Farr’s work between the 1830s and 1850s
[Vandenbroucke, 1985]. Farr explained that people were more
afraid of cholera than tuberculosis, not because of its ultimate
mortality, but because cholera kills more swiftly,
i.e. in lesser time: cholera kills in a week, while
tuberculosis may take years to kill; thus, the incidence of
mortality from cholera is larger. However, of all people with
clinical signs and symptoms of cholera, fewer die of that disease
than of all people who develop clinical tuberculosis; thus the
ultimate risk of cholera is less than that of tuberculosis.[Farr,
1838] Even today, the distinctions that Farr made - far ahead
of his time - continue to give rise to confusion.[Vandenbroucke
2004].
http://tinyurl.com/cwvu9w5
#3
How To Set Up Comparisons
Walter discusses case series, cohort, case-control,
randomized trial, and other designs in this essay. Here is
Walter’s introduction to case-control design
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