2. Etymology
(The study of the origin of words)
The word “epidemiology” originates
from the Greek words;
Epi (upon)
Demos (people)
Logy (study of)
3. Definition
Merriam-Webster:
1 : a branch of medical science that deals with
the incidence, distribution, and control of
disease in a population
2 : the sum of the factors controlling the
presence or absence of a disease or pathogen
4. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
5. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
6. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
7. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
8. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
9. Definition
Epidemiology is the study of the distribution
and determinants of health related states or
events in specified populations, and the
application of this study to control health
problems.
10. What is Epidemiology?
• The “basic science” and “backbone” of public health
• A powerful tool for studying community health
conditions
• The practice of “population medicine”
• An interdisciplinary field that draws from the social,
behavioral & mathematical sciences as well as from
the medical fields of toxicology, pathology, genetics,
microbiology and clinical medicine
It may seem rather juvenile to address the proper pronunciation of this word.However, I know from experience that some people, even health professionals, mispronounce the word, epidemiologyFor example, during my career as an epidemiologist, I have been called an:Epidermiologist (as if I am a skin doctor!)Epidemonologist (which sounds rather diabolical!)Epid’emologist (which sounds rather pitiful!)Epididymologist (!!!!)It is pronounced ep-i-dee-mee-ol-uh-jee
Epidemiology originates from the Greek words; Epi, demos and logyEtymologically, epidemiology is “the study of that which is upon the people”.Can you think of other words that originated from some of the same root words that epidemiology came from?epidermis, epithet, epidemic democracy, demographics
For any given word, there are of course, different definitions depending on the source.Mr. Webster defines epidemiology as shown here.
Epidemiology as defined by people in the profession, is shown here…..this is a working definition.There are several key elements in this definition that I would like to point out and expand upon.
First is the word, distribution.Epidemiology is concerned with the frequency and pattern of health events in a population…..i.e., their distribution, that is, frequency & patternFrequency – includes not only the number of such events in a population, but also the rate of those events in a population. Pattern – pattern refers to the occurrence of health-related events by person, place & time.
Next is the word, determinants.Epidemiology is also used to search for causes and other factors that influence the occurrence of health related events, i.e., determinants.Determinants are factors or events that are responsible for health/disease.In epidemiology, one wants to not only just describe health/disease events (i.e., descriptive epi) but also analyze these events.In descriptive epidemiology one looks at the frequency and patterns of disease (who, when & where….person, place & time)There is also analytical epidemiology where one looks at the determinants of disease and attempts to answer the Why and the How
Next is the term, ‘health related states or events’.Originally, epidemiology was the study of the distribution and determinants of disease, particularly communicable diseases.However, the field of epidemiology has grown/matured and has been extended to include the study not just of disease, but also health.Today, epidemiologic methods are applied not just to communicable/infectious diseases, but also to;Chronic diseasesInjuriesBirth DefectsMaternal-child healthOccupational healthEnvironmental healthIn this class, we’ll use the term “disease” to refer to a broad range of health-related states or events.
Epidemiology is a healthcare field….just like medicine. Epidemiology and medicine are similar in that they’re both concerned with health.However, there are differences;physicians deal with patients, epidemiologists deal with populationsTo an epidemiologist, their “patient” is the population,…. not the individual.For this reason, epidemiology is often referred to as “population medicine”.“Clinicians are concerned with the health of an individual; epidemiologists are concerned with the collective health of the people in a community.”
Last is the word “application”. The word implies action.Epidemiology is more than just “the study of”.As a health discipline, epidemiology provides data for directing public health action.Epidemiology is not just an exercise….it’s done for a reason. That reason is to protect and improve the health of our population.
Epidemiology has been referred to as the basic science and the backbone of public health.It is a powerful tool for studying the health of a population.Asalready noted, it is sometimes referred to as “population medicine”Also, it is an interdisciplinary field…..drawing from many other fields of study
The definition of epidemiology, etymologically, is “that which is upon the people”. “That which is uponthe people” can be very broad. Epidemiology is very wide-ranging in scope. The scope of epidemiology can be delineated by DiseaseExposure.
Let’s consider first, the scope of epidemiology as delineated by disease.Epidemiologyis not just limited to infectious diseases such as rabies, tuberculosis and hantavirus, but also to….Cardiovascular disease….. the study of risk factors for heart attacks and strokes.Cancer….. consider that the link between lung cancer and cigarettes was established not be tarot cards or tea leaves, but by epidemiology! Reproductive disease….. the study of risk factors for various birth defects, sudden infant death, stillbirth, spontaneous abortion, low birthweight, etcChronic disease…. examples includes heart disease, diabetes, and arthritis, asthma, COPDPsychiatric diseases….includes risk factors for insanity, depression, ADD or ADHD, bipolar, schizophrenia, OCDCan you think of other specific examples of the above general types of disease? All can be studied using epidemiologic methods!
The scope of epidemiology is delimited not only by diseases, but also by exposures…..some of which are listed here.Environmental epidemiology is the study of things such as silicosis and poisonings. Consider, for example, mesothelioma and Libby, Montana!Behavioral epidemiology….for example, liver cirrhosis, obesity and suicide…..very important/significant health topicsNutritional epidemiology…..the study of what foods and supplements are good/badDitto with drugs; pharmacoepidemiology. Clinical trials of drugs. How does the FDA establish the safety and efficacy of drugs? Nothing other than epidemiology!Injury epidemiology studies risk factors associated with motor vehicle accident’s, falls, seat belt usage, child safety seat and air bag safety, bicycle injuries and occupational injuries, etc.
On the timeline of the history of the world, epidemiology is relatively new. The study of the distribution and determinants of disease for the longest time wasn’t necessary because people had acceptable, alternative explanations for disease occurrencesIn the beginning, it was widely held that ill health and diseases were the result of “the wrath of the gods”In medieval times, foul vapors (miasma) emanating from the earth were suspected of being the cause of sicknessAnd then humors (bad things in our blood) resulted in the practice of blood letting (ala barbers) and leeches as a means of treating illnessesThe widely held myth of spontaneous generation was debunked by Louis Pasteur; this led to the germ theory of diseaseShortly thereafter, various types of microorganisms (bacteria, viruses, fungi, protozoa, parasites) were identified as etiologic agents of diseaseAnd then noninfectious agents (chemicals, radiation), behavioral characteristics (overeating, sun tanning), etc, were recognized to contribute to adverse health conditions. Disease came to be know as multi-factorial due to various determinants
Your textbook, under the subheading of “Foundations of Epidemiology” in Chapter 1, covers a variety of different people who helped lay the foundations of epidemiology. They include: -Hippocrates -Thucydides -William Farr -Edward Jenner -John Graunt -Robert Koch -Semmelweis, and othersYou can read about them if you want (Your not required to, and you will not be tested on them)The only “founding father” of epidemiology that I wish to cover in this introductory course is Dr. John Snow.All of you should the handout “John Snow and the Broad Street Pump”, and then address the discussion questions at the end.
![Epidemiology
pronunciation
[ep-i-dee-mee-ol-uh-jee]](https://image.slidesharecdn.com/damrowmodule1slides-120104130311-phpapp02/85/Damrow-module-1_slides-1-320.jpg)
