PHC 6001 Ch. 11 Confounding Exam
With 100% Correct Answers 2023
confounding - Correct answer-Which of the following can be thought of as a failure of
the comparison group to reflect the counterfactual experience of the exposed group?
*systematic difference* difference b/w groups being compared that distorts the true
association b/w an exposure and dz; an *inherent characteristic of the population
-occurs when the risk of dz in the unexposed group does not equal the risk of dz in the
exposed group had they been unexposed which means that the *difference in dz risk
b/w the exposed and unexposed is due to factors other than just the exposure*
Confounding Sources - Correct answer-1. experimental and cohort: occurs whenthe
exposed and unexposed groups differ by more than just the exposure, they differ by a
third variable
2. case control: occurs when cases and controls have *different characteristics*
confounding effects - Correct answer--results in distortion of the true association
between E and D. Can bias toward or away from null; can be adjusted for (or fixed) ...to
a point
-"mixing of effects" because the estimate of the effect of exposure on dz is distored b/c
it is mixed with the effect of other factors associated with the exposure and the disease.
Sometimes called the "third variable" problem.
DAG - Correct answer-Which of the following tools is a visual representation of the
relationship between a confounder, the exposure and the disease?
experimental studies - Correct answer-Which type of studies do not suffer from
confounding by severity mainly because randomization balances the severity
distribution of the compared groups?
literature review - Correct answer-Epidemiologists typically determine which variables
are potential confounders by conducting which of the following to ascertain all currently
known risk factors for the diseas under study?
randomization - Correct answer-Which of the following ensures that the treatment
assignment occurs in an unbiased fashion and will on average result in a balanced
distribution of both known and unknown confounders if the sample size is large
enough?
matching - Correct answer-Which of the following means that investigators select the
study subjects so that potential confounders are distributed in an identical manner?
Pros:
1. simple and effective control of characteristics being matched
