10. Association and Causation Flashcards
variable
any observable event that can vary
age weight
variables are either
associated or they are not
if not they are independent
if they are they are dependent
positively associated
they both increase and decrease together
negatively associated
they increase and decrease inversely
Types of association
no association = X and Y independent
associated = X does not cause Y (non-causally) X causes Y (causally)
independent variable
factor that stands alone and isn’t changed by other factor you are trying to measure
dependent variable
factor that is influenced or changed by another factor
Independent vs dependent
independent variable causes a change in the dependent variable and it is not passible that dependent variable could cause a change in independent variable
confounding variable
is interference bt third factor that distorts the association within a study of two primary variables
What are the illustrations of association
scatter plots
dose response curves
epidemic curve
contingency table
importan thing about causation
association does not prove causation
threshold
to the lowest dose at which a particular response occurs
epidemic curve
graphic plotting of the distribution of cases by time of onset
contingency table
tabular method of demonstrating association
central concern of epidemiology
one of the central concerns of epidemiology is to be able to assert that a causal association exists between an exposure factor and disease