cohort study

Question 1

What clasification of study does a cohort study fall under

Answer 1

An analytical observational epidemiologic study
- prospective study

Question 2

What are the 5 stages to a cohort study

Answer 2

1. Determine population
2. Randomly select a cohort
3. Define people control or exposed defined on preexisiting exposure
4. Follow up over ime
5. determine assocaition

Question 3

What are the measures of frequency and measure of associaiton used for a cohort study

Answer 3

Frequency = incidence, rate or preportion

Assocaition = Relative risk or risk difference

Question 4

What are the 2 core considerations which you must you consider for a cohort study

Answer 4

Determining our sample:
- rare exposures, may have to seperatly seected to control - mitigate group difference
- Ensure sample doesnt have outcome
Determining exposed: ensure correct clasification
Follow up overtime:
- How participance change exposure
- How many people have been followed up
- How long do people follow up for

Question 5

What are the strengths of a Cohort study

Answer 5

Can measure multiple outcomes
Rare exposures
temporal sequence
measure of incidence

Question 6

What are some weaknesses of a Cohort study

Answer 6

Long, expensive
Loss to follow up
rare outcomes require large sample size

Question 7

What is a historical cohort study -

Answer 7

retrospecitive cohort study using existing data - peopole are defined on past exposure then followup period is recreated to determine exposure

Question 8

Strengths and weaknesses of a histroical cohort study

Answer 8

Strengths - cheap/faster, rare, good for long time outcomes
Weaknesses - increased bias, miss defining exposure classification, poor retrospecitive data