What is an epidemiological study?
Epidemiological studies measure the risk of illness or death in an exposed population compared to that risk in an identical, unexposed population (for example, a population the same age, sex, race and social status as the exposed population).
What are the 3 major types of epidemiologic studies?
Three major types of epidemiologic studies are cohort, case-control, and cross-sectional studies (study designs are discussed in more detail in IOM, 2000). A cohort, or longitudinal, study follows a defined group over time.
What education is required to be an epidemiologist?
Master’s degree
What is epidemiology study design?
In epidemiology, researchers are interested in measuring or assessing the relationship of exposure with a disease or an outcome. As a first step, they define the hypothesis based on the research question and then decide which study design will be best suitable to answer that question.
What are the two types of epidemiology?
Epidemiologic studies fall into two categories: experimental and observational.
What kind of study would be best to study a rare disease?
Case-control studies are particularly efficient for rare diseases because they begin by identifying a sufficient number of diseased people (or people have some “outcome” of interest) to enable you to do an analysis that tests associations.19
What are the disadvantages of studying disease using a cohort study?
Disadvantages of Prospective Cohort Studies
- You may have to follow large numbers of subjects for a long time.
- They can be very expensive and time consuming.
- They are not good for rare diseases.
- They are not good for diseases with a long latency.
- Differential loss to follow up can introduce bias.
What type of study is a case-control study?
A case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute.
What are the strengths of a cohort study?
Strengths
- Multiple outcomes can be measured for any one exposure.
- Can look at multiple exposures.
- Exposure is measured before the onset of disease (in prospective cohort studies).
- Good for measuring rare exposures, for example among different occupations.
- Demonstrate direction of causality.
What are the pros and cons of using a prospective cohort study?
Because prospective studies are designed with specific data collection methods, it has the advantage of being tailored to collect specific exposure data and may be more complete. The disadvantage of a prospective cohort study may be the long follow-up period while waiting for events or diseases to occur.
Why is RCT better than cohort study?
Randomized controlled trials (RCT) are considered the best, most rigorous way of investigating interventional medicine, such as new drugs, but it is not possible to use them to test for the causes of disease. Cohort studies are observational. The researchers observe what happens without intervening.
What are the advantages of studying disease using a cohort study?
With data from cohort studies you can calculate cumulative incidences, which are the most direct measurement of the risk of developing disease. An added advantage is that you can examine a range of outcomes/diseases caused by one exposure (e.g. heart disease, lung disease, renal disease caused by smoking).
What are the disadvantages of epidemiological study?
Can obtain only a relative measure of risk (odds ratio) (however odds ratios are similar to risk ratios for rare diseases); are subject to recall bias; selection of controls may be difficult; temporal relationships may be unclear; can study only one disease outcome at a time.
What is the difference between a cohort study and a case control study?
Whereas the cohort study is concerned with frequency of disease in exposed and non-exposed individuals, the case-control study is concerned with the frequency and amount of exposure in subjects with a specific disease (cases) and people without the disease (controls).
Why are cohort studies not good for rare diseases?
One of the disadvantages of cohort studies is that they are more prone to selection bias. Studying rare diseases and outcomes that have long follow-up periods can be very expensive and time-consuming using cohort studies.4
Which type of study can be expensive and time-consuming?
Longitudinal studies
What are the strengths and weaknesses of case-control study?
Advantages: They are efficient for rare diseases or diseases with a long latency period between exposure and disease manifestation. They are less costly and less time-consuming; they are advantageous when exposure data is expensive or hard to obtain.7
Which is better case-control or cohort studies?
Retrospective cohort studies are NOT the same as case-control studies. In retrospective cohort studies, the exposure and outcomes have already happened. Therefore, cohort studies are good for assessing prognosis, risk factors and harm. The outcome measure in cohort studies is usually a risk ratio / relative risk (RR).6
What are the three types of longitudinal studies?
There are a range of different types of longitudinal studies: cohort studies, panel studies, record linkage studies. These studies may be either prospective or retrospective in nature.
What type of study is a prospective cohort study?
A prospective cohort study is a longitudinal cohort study that follows over time a group of similar individuals (cohorts) who differ with respect to certain factors under study, to determine how these factors affect rates of a certain outcome.
Does a cohort study need a control group?
Cohort studies differ from clinical trials in that no intervention, treatment, or exposure is administered to participants in a cohort design; and no control group is defined. Rather, cohort studies are largely about the life histories of segments of populations, and the individual people who constitute these segments.
When would you use a prospective cohort study?
Prospective Cohort Studies In this way, investigators can eventually use the data to answer many questions about the associations between “risk factors” and disease outcomes. For example, one could identify smokers and non-smokers at baseline and compare their subsequent incidence of developing heart disease.19
Is a cohort study quantitative or qualitative?
Experiments done in a laboratory will almost certainly be quantitative. In a health care context, randomised controlled trials are quantitative in nature, as are case-control and cohort studies. Surveys (questionnaires) are usually quantitative .
Is a feasibility study qualitative or quantitative?
Planning the feasibility study needs qualitative expertise to determine what can be done, how long it might take, how it is best done and the resources needed. It is therefore important that an expert in qualitative methods be included in both the planning and delivery teams for the feasibility study.7
What type of study is a feasibility study?
Feasibility study: “Feasibility studies are pieces of research done before a main study to answer the question ‘Can this study be done? ‘ They are used to estimate important parameters that are needed to design the main study”[1]. Data collected would not be analyzed or included in publications.
What type of study design is a feasibility study?
Feasibility studies are the initial phase of develop- ing an intervention. Conducting a feasibility study is a devel- opmental learning process in which the study procedures and intervention can be adapted as necessary during the study to achieve the most promising outcomes.
How do you create a feasibility study?
7 Steps for a Feasibility Study
- Conduct a Preliminary Analysis. Begin by outlining your plan.
- Prepare a Projected Income Statement.
- Conduct a Market Survey, or Perform Market Research.
- Plan Business Organization and Operations.
- Prepare an Opening Day Balance Sheet.
- Review and Analyze All Data.
- Make a Go/No-Go Decision.
What are the four types of feasibility?
Types of Feasibility Study
- Technical Feasibility. This assessment focuses on the technical resources available to the organization.
- Economic Feasibility.
- Legal Feasibility.
- Operational Feasibility.
- Scheduling Feasibility.