Cohort studies

Question 1

what is the relative risk

Answer 1

rate of disease in exposed / rate of disease in non-exposed

Question 2

what are the advantages of case-control studies

Answer 2

relatively inexpensive
smaller number of subjects
relatively quick results
suitable for rare diseases

Question 3

what are the disadvantages of case-control studies

Answer 3

incomplete information on exposure
biased recall
problems selecting control group and matching variables
yields only estimate of relative risk

Question 4

what are the advantages of cohort studies

Answer 4

lack of bias in determining exposure
yields incidence rates and relative risk
can yield association with additional disease outcomes as well as targeted outcome
efficient for studying rare exposures

Question 5

what are the disadvantages of cohort studies

Answer 5

possible bias in ascertainment of disease
large number of subjects required
long follow-up period
problem of attrition
changes over time in criteria and methods
very costly