How Do Epidemiologists Identify Risk Factors for Diseases?

Epidemiologists use various study designs to identify risk factors for diseases. These include:

Cohort Studies: Follow a group of people over time to see who develops the disease and who does not, comparing exposed and non-exposed individuals.
Case-Control Studies: Compare individuals with the disease (cases) to those without the disease (controls) to identify factors that may have contributed to the disease.
Cross-Sectional Studies: Assess the prevalence of a disease and potential risk factors at a single point in time.
Randomized Controlled Trials: Assign individuals randomly to receive an intervention or placebo to determine the efficacy of the intervention.