Transcription
Welcome! This is Medicos. Is perfection. Alice will start a new series on epidemiology. I know many students, oh hey, epidemiology and biostatistics. We will discuss all of these issues, and they are pretty simple once you grasp the concept. So let's get started.
When we discuss any topic for the first time, first we get the different roots of the word. This is called entomology, not to be confused with entomology, which is the study of insects. Okay. "Logy" means the study of, not necessarily science, but "-logy" means per se, like "death study." "Dimos" means population. "Epi" means upon. So, the study based upon the population.
So let's get the definition: The study of distribution and determinants of health-related events in a human population. Epidemiology is a medical topic because of health-related events. Why should you study epidemiology? As a doctor, you're only looking after an individual, a patient, but you are missing the general population. So, for instance, if you are a pediatrician dealing with kids, you will not get cases of type 2 diabetes. This does not mean that type 2 diabetes is rare among the general population. You're looking for individuals as a pediatrician, which are the kids, and you're missing the general picture. On the other hand, if you are taking care of elderly people—geriatric medicine—you will see a lot of type 2 diabetes. That doesn't mean that type 1 is negligible population. So we need epidemiology to see the big picture. Are we, as a country, doing better or doing worse? You can be a great doctor in your own practice, but if the cases of HIV/AIDS are increasing in the United States, we are not doing a good job, for example.
Why do I hate epidemiology? Because it's technical. It has a lot of vocabulary. It's not necessarily a science. I see it as a language, also an enemy is another example. When you study anatomy first, you get an introduction. You have to know the meaning of anterior, posterior, superior, inferior, medial, lateral, pre-post. If you don't know these words, you're screwed. Same stuff with accounting. It's technical. Let's say that you buy a bicycle for $100 and sell it for $150. What's your profit? The answer is $50. In accounting, you'll find there is a profit and net profit and gross profit and gross profit margin. So you will get lost, and you'll hate yourself. But the concept is pretty simple. You understand the scenario of the bicycle; you can understand accounting in a second. It's just technical; it has different language and vocabulary. Same case with epidemiology.
So epidemiology—there is with the population, not the individuals. Denominators are dominant. Denominators are way, way, way more important than the numerator. For example, let's say that there is a country with 100 cases of AIDS. Is this good or bad? I don't know. It depends. If the total population of your country is only 200 people, you are in a terrible position. That means that half of your populace have AIDS. That is not good. On the other hand, if you have 100 cases of HIV/AIDS in a population of 1 billion people, it's less bad than the first scenario. The 100 was the same; what differed was the denominator. That's why denominators are the kings. Denominators dominate. Okay.
Let's turn our attention to endemic, epidemic, pandemic. What's the difference? Endemic usually is a small population, such as one town, one city, or maybe one country, and the rate of the disease is pretty stable. For instance, I'm from Egypt. Let's say, Bilharzia is endemic in Egypt, which means Egypt is a single country; Bilharzia is stable in Egypt. It's not increasing or decreasing. Okay. Supposedly, epidemic is a larger population, usually more than one country, and there is a spike, sudden increase. For example, let's say that there is an epidemic of influenza in North America. North America is a continent; a spike of flu is called an epidemic, and influenza epidemic. Pandemic is different; it's worldwide. Let's say that Ebola spread to like every single country on earth, then it will be a pandemic, and of course, it's a disaster. See, epidemiology is not that hard. It's simple once you grasp the concept. See you in the next video.