Cohort studies examine the outcomes of a condition by looking forward. Researchers start with two groups: those who are exposed to a potential risk factor or intervention and those who are not. Then researchers follow those groups over time to compare what happens.
When to include: Cohort studies are useful if your question involves knowing about the long-term safety of an intervention. These studies can also be useful for effectiveness and exposure-related research if you can’t find useful RCTs.
Next up, case-control studies.