If, in trying to understand the causal relationship between an exposure and an o
ID: 3313757 • Letter: I
Question
If, in trying to understand the causal relationship between an exposure and an outcome, you fail to take an important confounder into account, you may:
A)
Underestimate the effect of the exposure on the outcome
B)
Overestimate the effect of the exposure on the outcome
C)
Underestimate the risk of the outcome in the population
D)
Overestimate the risk of the outcome in the population
E)
None of the above
A)
Underestimate the effect of the exposure on the outcome
B)
Overestimate the effect of the exposure on the outcome
C)
Underestimate the risk of the outcome in the population
D)
Overestimate the risk of the outcome in the population
E)
None of the above
Explanation / Answer
B) Overestimate the effect of the exposure on the outcome.
Suppose we are trying to understand the relationship between an exposure and an outcome. If we ignore or fail to consider an important confounder, then it means that there is another variable (the confounder) that is contributing to the particular outcome but we are completely ignoring its effect. Hence, we naturally tend to conclude that the outcome is because of the exposure only and NOT because of the combined effect of the exposure and the confounder which is the true scenario. As a result, we attribute the outcome entirely to the exposure, ignoring the outcome, thus overestimating the effect of the exposure on the outcome.