This week we are comparing and contrasting epidemiological methods of research; case-control and cohort study methods. Use the cohort study method and compare its features, the methodology, to a randomized controlled trial using the following questions. Please format, organize, your responses using each question below:
- What is the fundamental difference between the method you have chosen (either the case-control or cohort method) and the randomized controlled trial?
- What are the advantages and disadvantages of the study method you chose (case-control or cohort study)?
- What are the characteristics of a correlational study?
- Where does the method you chose (case-control or cohort study) fall on the research pyramid? What does where it is on the research pyramid mean?
Expert Solution Preview
Introduction:
In this assignment, we will compare and contrast the epidemiological research methods of case-control and cohort study. We will focus on the cohort study method and compare its features and methodology to a randomized controlled trial. We will discuss the advantages and disadvantages of the cohort study method, highlight the characteristics of a correlational study, and determine where the cohort study falls on the research pyramid and what significance it holds.
1. What is the fundamental difference between the method you have chosen (either the case-control or cohort method) and the randomized controlled trial?
The fundamental difference between the cohort study method and the randomized controlled trial (RCT) is that in the cohort study, the researcher observes a group of individuals over time and analyzes the development of an outcome or exposures between two groups, whereas in an RCT, the researcher randomly assigns participants to a group and manipulates one independent variable to determine its impact on an outcome variable.
2. What are the advantages and disadvantages of the study method you chose (case-control or cohort study)?
Advantages of a cohort study include the ability to study multiple exposures and detailed health outcomes over time, providing powerful evidence that can be applied to wider populations. Cohort studies are less prone to bias in the investigation of the causation since the study designs tend to avoid selection bias. On the other hand, cohort studies are often expensive, time-consuming, and can experience losses to follow-up. Disadvantages of case-control studies include the risk of bias because cases and controls often differ regarding their exposure distribution, making it difficult to generalize the results to the wider population.
3. What are the characteristics of a correlational study?
A correlational study is a type of research in which the focus is on the examination of a relationship between two or more variables, without necessarily determining a causal relationship. Correlational studies explore statistical relationships between variables in the dataset, examining variables’ pattern of covariation. Its principal disadvantage is that issues with validity may arise if a causal relationship is attributed to variables that are in fact not connected in any causal manner.
4. Where does the method you chose (case-control or cohort study) fall on the research pyramid? What does where it is on the research pyramid mean?
The cohort study falls under the observational study category on the research pyramid, which is the second tier. Research on this tier involves monitoring specific populations over an extended period, investigating their exposure to risk factors, progressing to specific diseases, and considering their experiences over time. Research on observational studies is useful for studying rare conditions or exploring the influence of behaviors or exposures on specific health issues. The research pyramid depicts the hierarchy of research evidence, with systematic reviews and randomized controlled trials indicating the highest quality of evidence, followed by observational studies, with case reports and expert opinions as the lowest level of evidence.
