What are the components of a case-control study?
What are the components of a case-control study?
Five steps in conducting a case-control study
- Define a study population (source of cases and controls)
- Define and select cases.
- Define and select controls.
- Measure exposure.
- Estimate disease risk associated with exposure.
- Confounding factors.
- Matching.
- Bias.
What is case-control study in epidemiology?
A case-control study is designed to help determine if an exposure is associated with an outcome (i.e., disease or condition of interest). By definition, a case-control study is always retrospective because it starts with an outcome then traces back to investigate exposures.
What are variables in a case-control study?
In a case-control study, ” participants are selected and categorized on the basis of the dependent variable (the outcome of interest). The purpose of the study is to test hypotheses about factors in the past (independent variables) that may explain the outcome” (Meininger, 2017).
How do you choose controls for a case-control study?
Selection of the Controls
- The comparison group (“controls”) should be representative of the source population that produced the cases.
- The “controls” must be sampled in a way that is independent of the exposure, meaning that their selection should not be more (or less) likely if they have the exposure of interest.
What sources can be used to identify controls for a case-control study?
Methods of Control Sampling
- Survivor sampling: This is the most common method.
- Case-base sampling (also known as “case-cohort” sampling): Controls are selected from the population at risk at the beginning of the follow-up period in the cohort study within which the case-control study was nested.
What are case control studies Slideshare?
Dictionary of Epidemiology: 3rd ed; John M Last. 2000) Case-Control Studies A case control study involves two populations – cases and controls and has three distinct features : Both exposure and outcome have occurred before the start of the study. The study proceeds backwards from effect to cause.
How many controls are in a case-control study?
Investigators planning case-control studies are usual- ly advised to include no more than four or five controls per case because little statistical power is gained by fur- ther increasing this ratio (1,2).
What are the advantages and disadvantages of case control studies?
Advantages and Disadvantages of Case-Control Studies. 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.
What are the types of case control studies?
The two types of case-control studies are: Non-matched case-control study: this is the simplest form. Find a person with the disease and enroll them in the study. Then enroll a control and determine their exposure status. Matched case-control: Find a person with the disease and enroll them in the study.
What is a case-control study?
A case-control study is a retrospective study that looks back in time to find the relative risk between a specific exposure (e.g. second hand tobacco smoke) and an outcome (e.g. cancer).
What is case control research design?
A case-control study is a research design used by researchers where the research begins with an outcome in order to comprehend the cause. Hence, this is a retrospective study.