Which is false about coho study
**Core Concept**
A cohort study is a type of observational study that involves the investigation of a group of individuals who share a common characteristic or experience over a period of time. This type of study is used to identify associations between exposure and outcome, and can help establish causality. In a cohort study, participants are followed over time to observe the development of outcomes.
**Why the Correct Answer is Right**
Cohort studies are useful for studying rare outcomes, and can provide valuable insights into the long-term effects of exposures. However, they can be resource-intensive and time-consuming to conduct. One of the key advantages of cohort studies is that they can establish temporal relationships between exposure and outcome, which is essential for determining causality. This is because cohort studies follow participants over time, allowing researchers to observe the development of outcomes after exposure.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not false about cohort studies. Cohort studies can indeed be used to investigate the effects of a particular exposure on a group of individuals.
**Option B:** This option is not false about cohort studies. Cohort studies can be used to identify associations between exposure and outcome, and can help establish causality.
**Option C:** This option is false about cohort studies. Cohort studies are not typically used to investigate the effects of a particular treatment on a group of individuals, as they are observational studies rather than interventional trials.
**Clinical Pearl / High-Yield Fact**
Cohort studies are often used to investigate the long-term effects of exposures, such as the effects of smoking on lung cancer risk. In order to establish causality, cohort studies must demonstrate a temporal relationship between exposure and outcome.
**Correct Answer: C. This option is false about cohort studies. Cohort studies are not typically used to investigate the effects of a particular treatment on a group of individuals, as they are observational studies rather than interventional trials.**