e****0
发帖数: 678 | 1 Please help me to clarify these two concepts.
Thanks |
h***a
发帖数: 312 | 2 Confounding: A situation in which the effect or association between an
exposure and outcome is distorted by the presence of another variable.
Positive confounding (when the observed association is biased away from the
null) and negative confounding (when the observed association is biased
toward the null) both occur.
* Effect modification : a variable that differentially (positively and
negatively) modifies the observed effect of a risk factor on disease status.
Different groups have different risk estimates when effect modification is
present..
If an observed association is not correct because a different (lurking)
variable is associated with both the potential risk factor and the outcome,
but it is not a causal factor itself,
THINK >> Confounding!
If an effect is real but the magnitude of the effect is different for
different groups of individuals (e.g., males vs females or blacks vs whites).
THINK >> Effect modification! |
n***a
发帖数: 1373 | 3 Confounding is a bias.
Effect modification is NOT a bias. It is real. It is an observation. |
d****y
发帖数: 2180 | 4 http://www.uic.edu/classes/epid/epid401/lectures/lecture5b.pdf
BTW, The more common name for effect modification is interaction. |
e****0
发帖数: 678 | 5 Very clear!
All of you are very smart!
【在 d****y 的大作中提到】
: http://www.uic.edu/classes/epid/epid401/lectures/lecture5b.pdf
: BTW, The more common name for effect modification is interaction.
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