cohort studies

Question 1

Question: What is a cohort study?

Answer 1

Answer: A cohort study is an observational study that follows a group of individuals over a specific period to investigate the relationship between exposure to a risk factor or intervention and the occurrence of outcomes.

Question 2

Question: How are participants selected in a cohort study?

Answer 2

Answer: Participants in a cohort study are selected based on their exposure status (exposed or unexposed) rather than their outcome status.

Question 3

Question: What are the two types of cohort studies?

Answer 3

Answer: The two types of cohort studies are prospective cohort studies and retrospective cohort studies.

Question 4

Question: What is a prospective cohort study?

Answer 4

Answer: In a prospective cohort study, participants are enrolled at the beginning and followed forward in time to track the occurrence of outcomes.

Question 5

Question: What is a retrospective cohort study?

Answer 5

Answer: In a retrospective cohort study, participants are identified based on their exposure and outcome status using historical data or existing records.

Question 6

Question: How is data collected in a cohort study?

Answer 6

Answer: Data in a cohort study is collected through methods like questionnaires, interviews, medical examinations, laboratory tests, and record reviews.

Question 7

Question: What is the primary measure of association in a cohort study?

Answer 7

Answer: The primary measure of association in a cohort study is the relative risk (or risk ratio), which compares the risk of developing the outcome in the exposed group to the risk in the unexposed group.

Question 8

Question: What are the advantages of cohort studies?

Answer 8

Answer: Cohort studies allow for the assessment of temporal relationships, evaluation of multiple outcomes, and provide more direct evidence for causality. They are useful for studying rare exposures or long-term outcomes.

Question 9

Question: What are the limitations of cohort studies?

Answer 9

Answer: Cohort studies can be expensive, time-consuming, and require long-term follow-up. Loss to follow-up and participant dropout can affect the validity of results. Confounding factors may influence the observed association, but statistical methods can help control for them.

Question 10

Question: What is the main purpose of a cohort study?

Answer 10

Answer: The main purpose of a cohort study is to examine the association between exposure to a risk factor or intervention and the occurrence of outcomes over time.