10
$\begingroup$

While drawing DAGs, we can define variables as exposure, outcome and unobserved etc. Could you please explain, what are instrumental and adjusted variables?

Improve this question
$\endgroup$

1 Answer 1

Reset to default
11
$\begingroup$

While drawing DAGs...what are instrumental and adjusted variables?

An instrumental variable is an observed variable that is often used to help obtain an unbiased estimate for a causal effect that is confounded by another variable that is usually unobserved. The classical situation can be depicted in the following DAG:

enter image description here

Here, X is our main exposure, and the causal effect of X on Y is confounded by U. Z is an instrumental variable for X: it is associated with X (and unconfounded) but not with Y; affects Y only via X; and both Z and Y have no common causes.

An adjusted variable is simply an observed variable which is adjusted for (ie. included as a covariate) in a regression model.

Improve this answer
$\endgroup$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.