In medicine, a<unk>  is a study that follows a group of people over time who have, or are at risk of developing, a specific medical condition or disease. A<unk>  collects health information over time to understand how the medical condition or disease develops and to give insight into how it might be treated. A<unk>  is often submitted when applying to the FDA or other regulatory agency as a baseline, to show the disease course for untreated patients. The<unk><unk>  data is compared to the disease course of patients given a proposed therapy to show the effects of the therapy.
Natural history study
Intersalt study
Cohort study
Population study
Multicenter trial
Parallel study
Randomized controlled trial
Placebo-controlled study