Final answer:
The three main steps of a case-control study are 1) Selection of cases and controls, 2) Data collection, and 3) Data analysis. Data interpretation is a subsequent step.
Step-by-step explanation:
When conducting a case-control study, there are critical steps that researchers must follow to ensure the integrity and validity of their findings. The correct order for these steps is:
Selection of cases and controls: This involves identifying subjects who have the trait of interest (cases) and a comparable group who do not have the trait (controls). It is not about the random assignment of cases and controls, which is more characteristic of randomized controlled trials (RCTs), another type of research methodology.
Data collection: This step requires gathering information from subjects about their past behaviors and exposures to identify potential correlations. In a retrospective study, this is done by asking subjects to recall their behaviors, which can introduce recall bias.
Data analysis: Statistical methods are utilized to compare the past exposures of cases and controls, thereby identifying any associations with the current status (such as the presence of a disease).
It is noteworthy that data interpretation, although an essential part of the research process, is generally considered a subsequent step after data analysis.
Examples like the classic case-control study by Doll and Hill on smoking and lung cancer provide a context for understanding how these steps are executed in practice.