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Epi Wit & Wisdom Articles
Epidemiologists Meet to Discuss
the Future of Epidemiology (2 of 3)
Should Epidemiologists Become
Social Scientists or Molecular Biologists?
Approximately 300 mostly
European epidemiologists gathered in Copenhagen on January 25 to
inaugurate the First International Panum Seminar and to discuss the
future of epidemiology. The meeting was organized by the Danish
Epidemiology Science Center, a research center established in 1994 by
the Danish National Research Found-ation. Organizers sought to
stimulate discussion around the future direction of epidemiologic
research. In particular, organizers wanted to learn whether
epidemiologists should head further “downstream” to identify the more
proximate causes of illness (often referred to as risk factor
epidemiology) or head “upstream” to understand broader factors
responsible for illness (often referred to as public health
epidemiology). To focus the presentations on this issue, many of the
speakers were given a question to answer, namely, should
epidemiologists become social scientists or molecular biologists?
Jorn Olsen, head of the Danish
Center and moderator of the proceedings, was clearly pleased with the
meeting. He told the Epi Monitor that the gathering provided a forum
for different points of view to be expressed. However, participants at
the Seminar seemed to be in general agreement that it would be useful
for epidemiologists to work at multiple levels, ranging the full
spectrum from the molecular to the individual to the population
levels. In short, epidemiologists should “feel at home” or be
“functional” in social science as well as in molecular biology.
David Hunter, Director of the
Harvard Center for Cancer Prevention and Associate Professor in the
Department of Epidemiology at the Harvard School of Public Health,
agreed with Olsen and called the meeting “really good... Everyone
agreed that epidemiology has a bright future, though there may be
questions about priorities... The take home message from the meeting
is that epidemiologists will need to think and train more broadly.”
Neal Pearce, Director of the
Wellington Asthma Research Group and one of the presenters at the
Seminar, also called it “very successful.” He told the Epi Monitor
that the presentations were received with great interest. He added,
“there is real change going on with many people recognizing that the
risk factor epidemiology approach is running out of steam and that we
need to rediscover the population perspective in order to revitalize
the field.” Furthermore, “there is growing recognition that all of the
approaches to epidemiology are important, but the population level has
been neglected...” according to Pearce.
Peter Aaby, Danish social
scientist who has been studying measles for many years in Guinea
Bissau, was one of the members of the discussion panel at the Seminar.
He agreed with Pearce that participants put epidemiology “squarely in
the public health field.” Stig Wall, Professor and Head of the
Department of Epidemiology and Public Health Umea University in
Sweden, said the Seminar revealed some polarization of views but less
than he expected. He supported the view that epidemiology has been
“too little concerned with the social factors in health and disease,
and has too much emphasized that we can find the explanation for
disease at the individual level.” He gave the example of smoking to
prove his point, citing the fact that we have known for decades that
smoking causes lung cancer but have not recognized that “the
interventive force” lies at the social level. Taking exception to an
idea presented in a recent paper in the Lancet by Ken Rothman, Hans-Olov
Adami, and Dimitrios Trichopoulos, he said “no one believes
epidemiologists should eradicate poverty, but we do in effect take a
stand if we choose not to study phenomena at that level.” He added
that a lesson learned has been the need for both qualitative and
quantitative approaches in epidemiology, but he emphasized his view
that risk factor epidemiology is not outdated as some have claimed.
“Of course,” Olsen said, “the
critical aspect is the funding. We can all agree to do studies at
different levels, but which level do we select when it comes to
priorities for research?” Organizers of the Seminar feared that
research funding is out of balance with too much money flowing to
projects that are focused on risk factor epidemiology. According to
Olsen, “there is a clear tendency towards this type of funding
currently in the European Union. Persons are not interested in
“old-fashioned” public health epidemiology with its broader scope.
Proponents of public health epidemiology have expressed the need to be
more outspoken about their views in order to counteract the current
trend, according to Olsen, and this was a driving force in hosting the
meeting. Dr. Wall agreed that there are funding problems, stating that
large scale public health epidemiology projects are expensive and
there is too little money for public health research.
Aaby was asked why there seems
to be a disconnect between what many believe should be the public
health orientation of epidemiology and the funding which appears more
in support of risk factor epidemiology. According to Aaby, there may
be more prestige and more potential economic benefit associated with
studying the most proximal risk factors for disease. “We all want the
magic bullet, the one intervention which solves the problem,” he said.
He gave the example of the focus on vaccine as the solution to the
control of measles rather than on other factors which could modify
transmission or mortality patterns. Walter Holland, visiting professor
at the London School of Economics, believes the disconnect in thinking
about funding comes from the fact that money is given by government
authorities and not by scientists. Also, risk factor epidemiology are
easier to carry out than projects addressing broader social causes of
illness and the implications of risk factor epidemiology findings may
be less threatening, said Holland.
Aaby noted that Pearce made an
“ingenious” suggestion at the Seminar to help reverse the favored
position of risk factor epidemiology. According to the suggestion,
health impact assessments should be required prior to funding
interventions or studies in epidemiology. These would be modelled on
the environmental impact statements that are required before
undertaking activities with environmental consequences. Such a move
would stimulate interest in public health evaluations and would
encourage the public health orientation, according to Aaby.
While many persons may be
sympathetic with the need to refocus epidemiology on population-level
determinants of disease, and while the need for doing this may seem
obvious to many persons, the benefits of this approach are not often
easy to demonstrate. This stands in contrast to risk factor
epidemiology which can point to proximate risk factors which can be
modified to reduce disease. Olsen used the example of cancer of the
cervix to illustrate this point. We know that human papilloma virus is
the proximate cause of illness which more distally is caused by having
multiple sex partners and that modifying factors include those related
to susceptibility and behavior. But does knowing and understanding
what drives some persons to have multiple sex partners constitute
epidemiology? Or is that more sociology and psychology? To use another
example, we know smoking causes cancer, according to Olsen. But is it
epidemiology to understand why people smoke? Perhaps Olsen and Wall
would give different answers to this question even though both seem to
reside in the “public health epidemiology camp.”
Despite these questions about
the broader approach to epidemiology, there seemed to be general
consensus among the participants that the presentation by Mervyn
Susser, Gertrude H. Sergievsky Professor Emeritus of Epidemiology at
Columbia, was the highlight of the seminar. Susser answered the
question posed by stating that “epidemiology, if it is to survive as a
discipline with a claim to common ground, must find room for and
encompass both social science and molecular epidemiology.”
Organizers of the meeting plan
to publish the proceedings of the seminar in an upcoming issue of the
International Journal of Epidemiology. Also, organizers of the
European chapter of the International Epidemiological Association plan
to host a satellite symposium on the future of epidemiology at their
next meeting in Lithuania in August of 2000.
The Panum Seminar included
presentations by six speakers. These presentations are summarized
briefly in the accompanying article, On the Future of Epidemiology.
Published February 1999 v
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