As a professor of Epidemiology, my primary goal is to teach my students how to read, critically analyze, and apply the results of an epidemiological study to create healthy communities. I want to empower my students to read research papers from beginning to end (not just the Abstract and definitely not skipping the Methods section). I want them to confidently read the literature, determine for themselves the strengths and limitations of the study, and be able to communicate the findings and any applications of those findings to a group of community members without any knowledge of epidemiology.
And I want to invite all of you into my classroom (so to speak). I want to provide you with a guide to reading the epidemiological research and the opportunity to read, discuss, and apply the findings of epidemiological studies with me.
Together — with improved literacy and the ability to see the strengths and limitations that are inherent in every study — we can fight misinformation, spot disinformation, craft strategies to improve health, and create healthy communities.
Are you ready?
Do you want to learn how to read, analyze, and apply the epidemiological literature?
Let’s get started… (if you missed either of the first two posts — Rule #1 or Three Things They Assume You Know — go back and read those first).
In literature, there is often a discussion of or readings from THE CANON.
The word CANON comes from the Greek word kanon, which translates to a measuring rod or standard. The literary canon (not to be confused with a cannon, a big military gun) is defined in a couple of ways —
Most commonly, the canon refers to the most important, influential, or authoritative works in the field. The canon is “intended to represent…our collective idea of which books you need to know in order to have a high-quality, well-rounded education.”
The canon can also be a body of work by a single author, like the Shakespeare canon.
In epidemiology, we have our own canon (so to speak). In some ways, it parallels the literary canon, but there are some (stark) differences. I would argue that there is an Epidemiological Canon - a set of influential and authoritative works that everyone should read. And like the literary canon, this list does change over time as new books are added to the canon.
In my opinion, the Epidemiology Canon is comprised of several essential textbooks, including Rothman’s Modern Epidemiology, Epidemiology Beyond the Basics by Szklo and Nieko, and Gordis’s Epidemiology. Additionally, the following books should be included in the canon — My Own Country, The Ghost Map, The Great Influenza, Beating Back the Devil, The Next Pandemic, And the Band Played On,1 The Coming Plague, Fears of the Rich, Needs of the Poor, House on Fire (the one by Foege), Mountains Beyond Mountains, Together, Silent Spring, Living Downstream, How to Survive a Plague, The Immortal Life of Henrietta Lacks, Polio: An American Story, When Breath Becomes Air, Complications, Bad Blood, and The Fever.
Unlike the literary canon that includes the body of work by a single author, the epidemiology canon focuses on the body of work around specific topics. There is the canon of cancer research, cancer risk factors, vaccines, screening tests, diagnostic and treatment options, disease outbreak investigations, clinical trials, public health surveillance, and more.
The canon of epidemiology is captured and summarized in the Introduction or Background section of every published paper. In the introduction section (that sometime is called the background), the authors of the paper summarize the canon of epidemiology as it relates to the research they have conducted and writing about. Specifically, they are highlighting the significance of the health problem their work centers around. They might cite public health surveillance data to show how prevalent a health problem is or other research highlighting the amount of death or disability that the health problem is causing.
After describing the health problem, the authors will document what is know about the risk factors or exposures contributing to new cases as well as whether nor not there are vaccines, diagnostics, screening tests, or treatments available.
Following this summary of what is known, the authors will describe what is unknown. Specifically highlighting what questions about the disease still need to be answered. It could be that we need more information about specific populations at risk or the effectiveness of a treatment. We might need to know if the prevalence of disease is different at one point in time compared to another. For example, are the number of cancer cases increasing in a community? or are we seeing more cases that we would expect to see?
After articulating what is unknown, the authors will use the final sentence (maybe two) in the Introduction section to clearly articulate the purpose or objective of their research. In essence, they will be stating how their work will be adding to the canon of epidemiology.
The Introducton section of every epidemiology paper summarizes the epidemiology canon in a structured format (what is the health problem, what is known, what is unknown, and what is the purpose of the research report you are about to read). Most Introduction sections in epidemiology papers are between 250-350 words in length and include citations from 15-30 other sources, specifically previously published papers, reports, or books, that are part of the existing canon of epidemiology.
Let’s look at an example…
Here’s an epidemiology paper focused on a pertussis outbreak in the England & Wales and the effectiveness of a maternal vaccination program.
The Introducton begins… and you can see from my notes, the authors start by identifying the health problem and details of the outbreak.
The Introduction concludes with the authors talking about what is known theoretically, but unknown from a practical/real-world standpoint. And then they are explicit about the primary and secondary objectives of their research.
NOTE: the Introduction includes 15 citations from the canon of epidemiology.
It is important to remember that individual studies do NOT exist in a void. They are adding to the canon of epidemiology. They are building on what is known. They are asking questions of what is assumed (see above, they assumed a few things theoretically, but wanted to know if those theories planned out in real-world settings). They are pushing to increase our knowledge about what causes disease and how we can prevent people from getting sick.
We build the canon of epidemiology so that we can work toward making statements of causation, but it takes work. And repeated studies. And layers upon lays of evidence.
We must demand that the authors of studies situate their work in the most up-to-date, valid, and reliable research that is out their. We must demand that they provide evidence about what is known and unknown. And that they connect their work to what has already been entered into the canon (through previous research).
That’s it… that is a summary of the Canon of Epidemiology and how that canon is summarized and how it grows with every new epidemiological study.
Next Tuesday we’ll move on to The Ethics of Studying Humans…
Be sure you are subscribed so you do not miss a thing.
Do you have questions about the Canon? Or how the Introduction section of an epidemiological paper is set up?
Or would you like me to share a homework assignment with you? Leave me a comment (like “sign me up” or “send the homework now”) and your email address. I’ll be sure to include an answer key!
Epi(demiology) Matters is written by Dr. Becky Dawson, PhD MPH — an epidemiologist, teacher, mom, wife, and dedicated yogi. She is a tenured professor at Allegheny College, Research Director at a community hospital, and an exclusive contributor (all things health & medicine) at Erie News Now (NBC/CBS). Her goal is to create healthy communities for all. She writes Epi Matters — first & foremost because epidemiology does matter (to all of us) and she hopes that each post will help to educate and empower readers to be healthy and create healthy communities.
Be sure you and your friends and family are subscribed so you don’t miss a post —
Epi(demiology) Matters is free — because science, reports, news, updates, and alerts about health should NOT be behind a paywall. EVER. Everyone needs access to up-to-date health information in order to be healthy and create healthy communities for all.
This book is the reason I am an epidemiologist. It is my inspiration. Reading this book truly changed by life.