Summary E-modules, course: Study Design and Interpretation in Epidemiology and Public Health

E-modules Samenvatting
Week 1: Cohort
Research Question: Is there an association between coffee consumption and risk of type 2 diabetes?
Study Design
- Observational
- Comparing outcome between persons
- Prospective cohort study




Prospective:




Simultaneous:

,Retrospective:




Population




Internal validity & External Validity

,Subject Selection




Information error:
- Random error
o Subjects are likely to over- or underestimate their coffee consumption and exposure
groups can look more similar than they actually are
- Systematic error
o When you e.g. overestimate systematically
- Also, errors in measurements of the outcome can introduce information bias

Confounding

, Summary




Glossary:

Internal validity: the extent to which the observed association between exposure and outcome in the
study population for analysis reflects the (unknown) true association in the source population.

External validity: the degree to which the observed association between exposure and outcome in
the population for analysis can be generalized to a target population

Target population: a broader population than the source population to which the investigator wishes
to generalize the association between exposure and outcome. This population is often not clearly
defined before the study is conducted

Source population: population with prerequisite characteristics (i.e. eligibility criteria) in which the
investigator wishes to assess the association between a certain exposure and outcome. It includes
potential participants and is defined before the study is conducted.