Epidemiological studies - made easy!
Where did this content come from
"Epidemiological Studies - made easy!" https://www.youtube.com/watch?v=Jd3gFT0-C4s&feature=youtu.be Watch this first and then learn the Quizlet here :)
What is an odds ratio?
(odds of being exposed - case)/(odds of being exposed - control) = odds ratio (OR) Odds ratio of more than 1 OR > 1 means that the cases were more likely to have been exposed to that risk factor A
1) What is a Case Series? 2) What is the purpose of a Case Series?
1) A Case Series study describes the characteristics of a group of people who have *the same disease* or *the same exposure.* 2) The purpose is the understand the demographics, clinical presentation, prognosis, or other characteristics of people who have a particular disease. Or... to describe something unusual: --> (ie. In the 1980's, the occurrence of an unusual pneumonia development in men which led to the recognition and identification of HIV).
Exposure is defined as
In epidemiology, the term *"exposure"* can be broadly applied to *any factor that may be associated with an outcome of interest.* When using observational data sources, researchers often rely on readily available (existing) data elements to identify whether individuals have been *exposed* to a factor of interest.
Prognosis vs. Diagnosis
The difference between the two is that while a prognosis is a guess as to the outcome of treatment, a diagnosis is actually identifying the problem and giving it a name, --> such as "depression" or "obsessive-compulsive disorder."
1) What is an Ecological Study? 2) What are examples of the size of an Ecological Study? 3) Whom do Ecological Studies apply to? 4) What are Ecological Studies useful for?
1) A type of study where measurements like *disease rates* and information about *exposures* are made on a group of people. 2) The groups can be as *small as people in a house* or as *large as people in an entire country.* 3) Results and conclusions from Ecological Studies *apply to a group, not to individuals* 4) Ecological Studies are useful for *comparing the health of people in different places (ie. measles rates in Australia vs New Zealand) or at different times (1997 vs 2007).
What are some examples of a question for an epidemiological study?
1) Does smoking cause cancer? 2) Is there more disease in an area (ie. Australia) compared to another (ie. New Zealand)? 3) What food is responsible for causing an outbreak?
1) What does a Cross-sectional Study do? 2) How do you conduct a Cross-sectional Study? 3) What is an example of a Cross-sectional Study? 4) How are Cross-sectional Studies related to *"prevalence"*? 5) Strengths of Cross-sectional Studies? 6) One major limitation of a Cross-sectional Study?
1) Takes a selected population and measures health information at a given point in time --> this gives a snapshot of their health. 2) This usually involves asking participants a series of questions (ie. using a questionnaire). 3) Health surveys that collect information about people in a population is an example of a Cross-sectional Study. 4) Because Cross-sectional Studies commonly measure *how many people have a disease at a particular point in time,* they're also called *Prevalence* Studies. --> So it is important to make sure that the selected population is representative of the total population. 5) Cross-sectional Studies are: - relatively *inexpensive* - *easy to conduct* compared with other studies - can provide information on *multiple* exposures and outcomes - good way of *assessing the health needs of a population* 6) However, since the information is collected at a single point in time it *cannot be used to decide whether a particular exposure *caused* the disease or not.*
How do we think about designing a study? (5 steps of designing and completing a study)
1st We need a study question 2nd Select a study type (ie. Ecological, Case Control, Cohort, Intervention) 3rd Collect and analyze data using a suitable statistical method 4th Interpret result to make sense of the data 5th Report result finding of the study ALL DONE IN AN *ethical* way :)
What is an epidemiological study?
A scientific process of answering a question using data from a population
What is a case-control study?
Starts off with "Cases" (people with a disease) and uses a comparison group called "Controls" (people who do not have the disease). Controls are similar to cases in as many ways as you can "control" for, but as stated above, do not have the disease. Then, both groups are asked about their previous exposures to different risk factors (ie. past exposures: - risk factor A - risk factor B - risk factor C - risk factor D Now, for for each of the risk factors (ie. risk factor A), the *odds* of being exposed if they were a "Case" is compared with the odds of being exposed if they were a "Control." This is called an *"odds ratio"* (odds of being exposed - case)/(odds of being exposed - control) = odds ratio (OR) Odds ratio of more than 1 An OR > 1 means that the cases were more likely to have been exposed to that risk factor A So, An OR > 1 = associated with disease
Prevalence is:
The number/proportion of cases of a particular disease/condition present in a population at a particular point in time.
