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CHAPTER 17: Investigating the Types of Epidemiologic Studies
Introduction
As a beginner in public health, you may be on a quest to know about diseases that are affecting your community, other countries, and the world. If you desire to build a career in a field of epidemiology, you want to know more about what causes certain diseases and how they’re transmitted, or as a public health professional, you want to advise people about disease prevention.
You’ve come to the right place. Epidemiology has been a hot topic in the past few years with the Covid-19 pandemic, but there’s so much more to it. Getting a degree in epidemiology is a good choice because the concepts and skills of epidemiology will prepare you for plenty of jobs in public health. Even if you aren’t a researcher or a data analyst, epidemiology can help you get a sense about numbers when you hear that the Covid-19 rates are rising or coming down, or when you hear that Forest County of Hattiesburg, Mississippi is the hot spot of lead poisoning.
About This Book
Epidemiology For Dummies emerged from the needs of undergraduate and graduate students in public health, especially in the field of epidemiology. During the Covid-19 pandemic, almost all face-to-face classes were closed and classes were only offered online. Some students faced challenges in fully understanding some difficult topics during this online format.
This handy guide isn’t a textbook or workbook in epidemiology. Rather, I wrote this book based on my decades of experience in practicing medicine, conducting health research, and teaching public health for undergraduate as well as graduate students to help explain the concepts of epidemiology in plain English with plenty of real-life examples, calculations, and illustrations.
Here you can read about an array of concepts, starting from Epidemiology 101 to more advanced research methods to ethics in conducting human research. I focus on the following areas:
» The history of the development of public health and epidemiology
» The epidemiologic triangle
» Person-place-time distribution of diseases
» Causal association and Hill’s criteria
» The three levels of prevention
» Vaccine-preventable diseases
» Disease surveillance
» Steps of outbreak investigations
» Screening methods
» Epidemiologic study designs
» Bias and confounding
» Population projection
» Ethics in human research
I also provide step-by-step explanations and answers to practical issues like the following:
» Investigating outbreaks and analyzing data
» Solving problems of sensitivity, specificity, and predictive value
» Calculating commonly used rates, ratios, and proportions
» Calculating incidence, prevalence, and standardized mortality ratio (SMR)
» Calculating country-level data for population projection
Foolish Assumptions
When writing this book, I’ve made a few assumptions about you, my dear reader. I made the following assumptions:
» You’re bored or somewhat disappointed by reading textbooks with small fonts, full of concepts after concepts, with few examples of topics that don’t provide real-life examples of epidemiologic applications.
» You’ve struggled understanding some of the technical terms and concepts in epidemiology, but you see your future working in public health.
» You’re excited about applying what you’ve studied in your epidemiology courses, but you need a little extra help with the calculations.
» You’ve been working a few years in a health department and you’ve faced many issues, such as choosing the right study design based on your resources, preparing a questionnaire, or investigating and controlling an epidemic.
» You’re a silent learner, and you don’t ask questions in a class.
Icons Used in This Book
Throughout this book, you can find icons — small pictures next to the text that point out extra-important information. Here’s what they all mean:
For gems of accumulated wisdom — quite often the kind learned by painful experience! — follow this icon.
Consider this icon like a stop sign. When you see it, stop and pay extra attention because you might make a mistake — perhaps in a math calculation or something extra important — if you’re not careful enough.
You’re trying to do things correctly and efficiently. Problem is, you may not always know what’s right and what isn’t. When you see this icon, pay attention to the text.
This icon is used for more advanced material that you don’t need to read to understand the concept at hand. It’s information that’s interesting but not absolutely essential.
This icon points out concepts with practical examples, some from my own research.
Beyond This Book
This book is chock-full of tips and other pieces of helpful advice you can use as you study epidemiology. I provide links where you can go online for more information. In addition, check out the book’s Cheat Sheet at www.dummies.com and search for “Epidemiology For Dummies Cheat Sheet” for information to reference on a regular basis.
Where to Go from Here
This book represents a starting point for concepts and uses of epidemiology. Your new learning curve in public health is just beginning. So, now what? You can flip through the Index or Table of Contents to find a subject that interests you.
Or you can turn to whatever section looks to have the answers and information you’re wanting most. No matter where you start, you can read a section or two, stop, and then come back when you need more guidance. I tell my students, “Epidemiology is easier than you think and more fun than you can imagine.”
1 Getting Started with Epidemiology
IN THIS PART . . .
Gain a basic knowledge about infection and infecting agents such as bacteria, viruses, parasites, yeasts, molds, and others; how diseases occur, and why you are not sick all the time despite living in a world with so many infecting agents.
Get background information about how the science of modern-day epidemiology came into play through different stages of legendary works in the field.
Understand the scope of epidemiology, two major functions of epidemiology, and the importance of epidemiology in measuring health status, searching for disease causation, and controlling and preventing diseases and events in humans.
Identify sources of epidemiologic data such as the Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), census data, vital statistics, and others.
Explore older and modern theories of diseases causation and important contributions of people in laying foundation and the development of different branches of public health.
Uncover milestones in public health, such as James Lind’s study of finding the treatment for scurvy, the cholera investigation of John Snow, Joseph Goldberger’s study of the cause of pellagra, the famous influenza pandemic, the eradication of smallpox, the connection between smoking and cancer, the development of theories of causal association, and more.
Recognize the means and ways of controlling several common infections, such as waterborne diseases, airborne diseases, vector-borne diseases, parasitic diseases, and sexually transmitted infections.
