Which of the Following is an Example of a Cohort

Question

Which of the following is an example of a cohort study?
A) Compare lifetime exposure to coal plant emissions between individuals with lung cancer and individuals without lung cancer in the general population.
B) Measure lifetime exposure to coal plant emissions and the incidence of lung cancer in a group of individuals living in a small town.
C) Question all people in an area about their exposure to coal plant emissions and whether they have any lung diseases.
D) Examine the incidence of lung disease in all females over the age of 50 in a city by a coal plant.

Accepted Answer

A cohort study involves following a group of individuals over time to assess the relationship between exposure to a particular factor and the development of a disease or condition. In option B, the group of individuals living in a small town are being followed over time to see if there is an increased incidence of lung cancer due to their exposure to coal plant emissions. This fits the definition of a cohort study. Options A, C, and D are not examples of cohort studies because they do not involve following a specific group of individuals over time. Option A and D are case-control studies, where individuals with and without the disease are compared retrospectively to determine exposure. Option C is a cross-sectional study, where individuals are assessed at a single point in time for both exposure and disease status.