Epidemiological Studies - made easy!May 30, 2022
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studieslet's take a quick look at
studieswhat are some different types of studies their advantages and disadvantages first of all what is a good study in a nutshell a study is a scientific process of To answer a question using data from a population, it can be any question, for example, does smoking cause cancer, is there more disease in one area compared to another, or what foods are responsible for causing an outbreak, so the first thing you should to do in any study is we have a study question what are we trying to find out then we need to figure out what is the best type of study that would help us answer the question once we have decided on a type of study we have to do the study collect and analyze the data using a suitable statistical method, then we need to interpret the results to make sense of it all and finally e must report the results of our study, most importantly, all studies must be conducted in an ethical manner, now let's take a look at some different types of studies an ecological study is the type of study in which they are conducted measurements such as disease rates and information about exposures in a group of people groups can be as small as people in a house or as large as people in an entire country, it is important to remember that the results and conclusions of ecological studies apply to a group and not to individuals.
Ecological studies are useful for comparing the health of populations in different places, such as measles rates in Australia and New Zealand or at different times. they are also useful for generating questions and highlighting issues that may lend themselves to further research or study a case series describes the characteristics of a group of people who have the same disease or exposure the goal of this is to understand the demographics clinical presentation prognosis u other characteristics of people who have a particular disease or describe something about you, for example, in the count and 1980s the occurrence of unusual pneumonia in men led to the recognition and identification of HIV a cross-sectional study takes a selected population and measures health information at a point in time by giving a snapshot of their health usually involved asking participants a series of questions using a questionnaire health surveys that collect health information about people in a population is an example of a cross-sectional study because these studies commonly measure how much he people have a disease at a particular time are also called prevalence studies It is important to ensure that the selected population is representative of the total population.
Cross-sectional studies are relatively inexpensive and
easyto perform compared to other studies. They can provide information on multiple exposures and outcomes and are a good way to assess the health needs of an individual. However, because the information is collected at a single point in time, it cannot be used to determine whether a particular exposure caused the disease or not, a case-control study begins with cases who are people with a disease uses a comparison group called controls who are similar to the cases but do not have the disease then both groups are asked about their exposures prior to different risk factors now, for each of the risk factors, the odds of being exposed if they were a case are compared to the odds of being exposed if they were a control this is called an odds ratio an odds ratio of plus On average, people with the disease are more likely to have been exposed to that risk factor than people with the disease. people without the disease this suggests that it could be a possible cause of the disease an odds ratio of less than one suggests that it is a protective factor and one suggests that it is not Case-control association studies are commonly used in outbreak investigations For example, we can compare the odds of eating different types of food among people who got sick after contractions. eating a meal and those who did not If the odds ratio is greater than 1 for a particular type of food, then it is possibly the cause of the disease.
A great advantage of case-control studies is that they are often quick and cheap to make too because they start with cases, can be used to study rare diseases; however, because these studies involve small numbers, they are not good for studying rare exposures. One of the challenges in a case-control study is finding suitable controls as well because the studies ask. about exposures in the past and people may not be able to remember their exposures accurately let's look at cohort studies now in a cohort study a group of people have been followed over a period of time to see what happens to them and information on risk factors is collected we can compare the occurrence of an outcome such as a disease in those who are exposed to a particular risk factor with those who are not exposed to that risk factor the main measure used in cohort studies is termed risk relative a relative risk is the ratio of the risk of disease in the exposed group compared to the risk of disease in the unexposed group a relative risk greater than 1 means that the exposure is associated with an increased risk of disease if it is 1 indicates that the risk is the same and if it is less than 1 it indicates that the risk is lower a well-known cohort study is the study io of British doctors conducted in the 1950s where a group of doctors were followed for many years, this study provided valuable scientific evidence of the harmful effects of smoking, especially the relationship between smoking and lung cancer.
One of the main advantages of cohort studies is that the temporal sequence of events can be determined. This is useful when trying to determine what caused a disease. Another advantage is that information on several different outcomes and risk factors can be collected at the same time. This allows for some analysis of the data. A disadvantage. The most important thing about cohort studies is the high cost and they can involve a large number of people who must be followed for a long period of time. They are generally not suitable for studying rare diseases. A challenge in cohort studies, especially those carried out over a long period of time. time is to ensure that the people who started the study stay until the end of the study if many people drop out it will affect the results of the study now let's look at another type of study an intervention study in an intervention study an intervention is done in a group of people and the outcome being studied examples of interventions might be giving a medication a vaccine or health advice the outcome might be things like a change in disease state or a change in behavior a randomized controlled trial is the best study design for a intervention study say we want to study the effects of a new drug, we start with a study population, then people are randomly assigned to be in the intervention group where they receive the drug or in the control group where they do not receive the medication after an adequate period of time, the results in the two groups are evaluated and compared ran to see what effect the medicine had.
Outcomes can be things like a change in disease symptoms or death rates, ideally neither the participants nor the investigators should know which group received the intervention this is called double blinding and ensures that neither can influence the outcome. study outcome the main advantage of a randomized control study is that it can provide good evidence that the intervention led to a randomization of the results ensures that both groups have an equal chance of receiving the intervention and have similar characteristics. In this way, the effect of the intervention can be determined without other factors influencing the result. The downsides are that these studies are usually quite expensive. it also requires a large number of participants, it may not be appropriate in some situations where we are not providing an intervention, it may be inappropriate or unethical, finally, it is sometimes difficult to keep up with all the studies that have been done on a topic in particular, but fortunately there are studies that summarize other studies, there are two main ways this is done, a systematic review systematically identifies all relevant studies on a particular topic assesses the quality of each study synthesizes and interprets the findings and presents a unbiased, unbiased and balanced summary of the evidence a meta-analysis uses data from all studies that have addressed the same question and have a study design, then uses the data from these studies to do a combined statistical analysis and produces a single summary result, which is a general description of some of the types of epidemiological studies commonly used. lysed.
We have taken a look at what a study is. advantages and disadvantages
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