Cohort

Question 1

What is a cohort study

Answer 1

longitudinal, observational study looking at exposures and outcome

Question 2

Advantages of cohort study

Answer 2

Exposure precedes outcome so temporality
Efficient for rare exposures
Can look at multiple outcomes
Minimises recall and selection bias

Question 3

Disadvantages cohort study

Answer 3

Expensive
Time consuming
Loss to follow up may cause bias and poor generalisability
Inefficient for rare disease
Change to diagnosis/practice may cause bias

Question 4

Prerequisites cohort studies

Answer 4

Both cohorts disease free
Both = susceptible to disease
Comparable group e.g. matching
Diagnostic criteria should be defined in advance