strength of association
-stronger association; gives us a more compelling case for causality
consistency in repeated analyses
-repeated observation across different populations or circumstances
a single effect
In order for a causal relationship to be true, a cause must lead to ________.
cause must precede the effect in time
What must be the case in regards to the timing of cause & effect in regards to causality?
biological gradient
-dose-response or duration-response relationship
plausibility
-the existence of foundational scientific or biological theory
OR=1
The event rate is the same in the treatment and control groups. (O)
OR>1
The event rate in the treatment group is higher than the event rate in the control group. (O)
OR<1
The event rate in the treatment group is lower than the event rate in the control group.
RR=1
Implies no difference in risk of the outcome between the groups. (R)
RR>1
Implies a greater risk of the outcome in the treatment group. (R)
RR<1
Implies a lower risk of the outcome in the treatment group. (R)