The scope and challenges of epidemiology
Idea 1: The uses of epidemiology are many, but shift over time, and are subject to recurrent challenges from inside and outside the field.
Idea 2: In advising on the most effective measures to be taken to improve the health of a population, epidemiologists may focus on different determinants of the disease than a doctor would when faced with sick or high-risk individuals.
(Make annotations in alphabetical order by author's name and at the end of your entry add your initials and the year you're taking the course.
Guidelines)
Notes and annotations on idea 2 from 2007 course
Initial notes from PT
Idea 1
Idea 2
Rose promotes the population health focus, but this is not universally accepted by healthcare practitioners and policy makers. Can you identify areas in your own life and/or work when you would take a population view and other areas where your focus would be individually-centered?
(11/07) Road accidents and alcohol consumption may be a good illustration of Rose's argument. Most of us know of getting home safely when we've drunk too much "risk factor," but we also know that a substantial fraction of people in accidents have high alcohol levels. We also sense that some people are more susceptible to having their judgement and reaction times impaired by alcohol so we could imagine doing further epi & biol research to develop multivariable risk factor formulas. Would a more refined knowledge of riskiness help us prioritize our risk-prevention efforts, or would that pale into insignificance relative to a Rosean drink-don't-drive efforts?...
Controversy over vaccination of girls for HPV, given the physical side effects (at a low rate -- see
http://www.usatoday.com/news/health/2009-08-31-hpv-gardasil_N.htm) and promiscuity-inducing side effects (no data for this). Question: What would Rose propose?
Question in class: Why isn't a population an aggregation of individuals and thus population risk = sum of individual risks?
PT's response: It is necessary to think of different meaning of "treatment." A sick individual is treated by a physician to cure or reduce the effects of the disease. Population health policies do not treat a large group of sick people, but attempt to reduce the incidence in the next generation. A physician treating sick individuals adjust the treatment if it doesn't work well for certain individuals. Public health measures usually discount the heterogeneity in the population and apply the same policy to all. It is possible, however, to imagine that knowledge of heterogeneous responses to treatment of individuals could lead to more effective population health policies (and reduce the kickback that occurs when some individuals claim to have suffered under the population health policy).
Initial notes from MC
In the two shared readings for today there is this theme of the discipline of epidemiology as being able to explore different paths of learning and investigation. In Davey Smith's (2001) article he quotes Stephen Frankel's use of the phrase "epidemiology of indications" (p. 1149) where the appropriate parameter is to look at the number of people in a population who can benefit from medical treatment, rather than the number of people with a particular condition. This echos the argument of Rose (1985) who outlines two approaches to epidemiology (and though he doesn't call it this, public health in general): the high-risk strategy and the population strategy. Rose lists the advantages and disadvantages of both, claiming they both are necessary and not particularly at odds with the other, but that the priority of epidemiologists should always be the population strategy--discovering and controlling the causes of incidence, which is the "epidemiology of indications" put differently.
I noticed that these readings take for granted a key issue of epidemiology that we discussed last week. (I'm not saying this as a critique, it makes sense in light of us building our knowledge every week.) But it's worth noting again that so much of epidemiological work, especially the more theoretical pieces like this weeks readings (on the scope and challenges of epidemiology), have to point to real, hard data to back up any assertions. That need for data links back to the absolute importance of data collection and an infrastructure that allows for data collection.
And in light of our continued discussion about the goal of epidemiology, I think it's worth repeating the question Rose's mentor posed, "Why did this patient get this disease at this time?"
Annotations on common readings
Annotated additions by students
Antagonism and Accommodation: Interpreting the Relationship Between Public Health and Medicine in the United States During the 20th Century (Brandt and Gardner, 2000)
As someone who got interested in public health research and policy through working on research projects, I still feel like I have a lot to learn about the history of health in the U.S. This paper has provided some insight into the development of the Public Health field, as well as the obstacles and stereotyping public health experienced in the past century.
I found particularly interesting reading about the relationship between public health and medicine, and the opposition physicians showed against the increasing role of public health. Some of the arguments aimed to diminish the role of public health reminded me of AMA’s (American Medical Association) position against universal healthcare in the past century.
A probably “naïve” position would be to expect that physicians would always have patient’s well-being as their highest priority, as per Hippocrates Oath. Looking from that position, contributions made by public health professionals would be seen as beneficial to advancement of population health and medical science in general. Similarly, universal healthcare would be seen as a way to ensure that sick individuals get needed care, that the appropriate prevention against diseases is in place, and to ensure we have healthier population.
Contrary to this “naïve” position, physicians have been expressing skepticism toward public health body of knowledge, as well as stereotyping and labeling (“communists”) to discredit major efforts of public health professionals. Brandt saw the physicians’ opposition, even “hostility” (p.711) against public health as “a reflection of self-interest” and fear for “their financial well-being” (p.711).
While there is agreement about the usefulness of public health for providing quantitative assessment of new interventions (p.712) and its role in evaluating patient safety and healthcare quality (p.713), Brandt argues that this is a reductionist position, and that public health provides valuable research beyond evaluation and assessment, especially in regards to social, cultural, and economic factors of diseases (p.713). Given that the top causes of illness and death shifted from infectious to chronic diseases, understanding these other-than-biomedical factors and putting them in equation is critical for comprehensive health research and delivery of care (DBJ, 09).
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This piece describes the history of tensions between public health and medicine. Clearly written by public health experts, the article claims that medical doctors should acknowledge the need for public health.
Brandt and Gardner trace back to the time when “medicine” and “public health” were broader disciplines that were more closely aligned. He claims that as each discipline became more separate there grew a boundary separating the two, in which the disciplines began to see disparities in status and authority (pp. 708-9).
The most interesting element to Brandt and Gardner’s piece is the historical basis for the divide between medicine and public health and how it plays out politically. From my experience and understanding, doctors individually and doctor’s groups like the AMA tend to be critical of calls for universal health care and other measures that public health professionals see as benefiting all. And like Brandt and Gardner describe, public health professionals are more willing to see individual rights limited for the good of the majority. For me, that’s a difficult issue, and not necessarily one that can find a compromise. Individual rights and sovereignty are generally well respected in American society. Public health measures that impede those rights do so for the greater good, but the pushback from American society is understandable. So it is interesting to me to read this abbreviated version of two factions that debate this issue.
Also, the rise of the “biomedical paradigm” (p.711) was intriguing. As Brandt and Gardner claim, this paradigm “uncouples disease from its social roots” and is appealing because of its scientific objectivity (p.711). For my research interests, particularly with CAM practices, it would be interesting to explore more this rise of biomedicine and how that has shaped opinions of and responses to CAM practices. (MC, 09)
Traditional Epidemiology, Modern Epidemiology, and Public Health (Neil Pearce, 1996)
This article considers modern and traditional approaches in epidemiological methodology. Neil Pearce elaborates on some of the changes that have occurred in epidemiological research over the years. He clarifies for the reader, the distinction between what he refers to as traditional epidemiology and modern epidemiology. Also of importance is the change in the level of analysis from the population to the individual. He goes on to discuss how epidemiologists learn their craft, and he provides his readers with a historical overview of epidemiology.
One particular area of interest for him is that modern epidemiologists have little concern for the socioeconomic factors that may affect health, and that it has taken a back seat in the study of epidemiology. There is also mention of how traditional epidemiology has somewhat fallen out of favor. He is dismayed at the disinterest in notion that population factors are related to causes of disease, where there is more focus on treatment and prevention rather than causality. He attributes this in part to the lack of funding by government agencies, and the personal situations of epidemiologists. He notes that government does not view socioeconomic studies as “sexy” and that they have little to no concern for socioeconomic factors or health.
Pearce describes what is known as the “bottom-up” and “top-down” approaches. The latter begins at the population level in order to determine the primary factors that effect health, and it uses the structural model of causation. The bottom-up approach is quite the opposite in that it begins on the individual level and proceeds upward toward the population level – molecular epidemiology is an example given by Pearce.
In sum, epidemiology has basically stopped working as part of a multidisciplinary approach to understanding the reasons for disease in populations and has become a set of generic methods for calculating associations of exposure and disease in people. This approach focuses on the person, blames the victim, and interventions are produced that can be harmful. Moreover, technology is being used to study trivial issues, while the major causes of disease are overlooked. Pearce appears to have a preference for the population perspective and would like to find a way to preserve that while at the same time, utilizing some of the current epidemiological methodologies. (CH)
