Final answer:
In a cohort study, there are generally two main groups involved: the exposed and the unexposed (or comparison) group. These groups allow researchers to compare outcomes over time to study the potential effects of exposures on the development of diseases or conditions and to calculate relative risks.
Step-by-step explanation:
In a cohort study, different kinds of groups can be involved, primarily including the exposed group and the unexposed group (or comparison group). The exposed group consists of individuals who have been exposed to the factor of interest, for example, a new medication or a potential risk factor for a disease. The unexposed group, on the other hand, comprises individuals who have not been exposed to the factor in question.
The purpose of these diverse groups within a cohort study is to compare the outcomes between them. By following both groups over time, researchers can observe and record the incidence of outcomes, such as the development of a specific disease. The comparative analysis helps in establishing the sequence of progression of disease states or other conditions of interest and in determining the relative risk associated with the exposure.
It should be noted that the statement, 'A cohort is a group of subjects of different ages, weights, genders, and health statuses' is False. A cohort typically refers to a group of people who share a particular statistical or demographic trait such as the same exposure or a specific age group.