Causality, Confusion, and Interaction in Health Sciences Statistics

In the context of epidemiology, what is a causal relationship between an exposure E and an outcome D defined as?

A relationship where the correlation coefficient between E and D is less than 0
A relationship where E and D are statistically independent
A relationship where E follows D in time
A relationship where there is a significant statistical association between E and D (correct)

What should be considered before assuming a significant association between a given exposure and a given health outcome?

The presence of other confounding variables (correct)
The geographical location where the exposure occurred
The individual's genetic makeup
The day of the week when the exposure occurred

Which of the following study types requires that exposure E precedes outcome D?

Cross-sectional study
Ecological study
Cohort study (correct)
Case-control study

In causal mediation, what does a mediator M represent?

An intermediate step between exposure E and outcome D (B) Signup and view all the answers

What is the main challenge in modeling causation in epidemiology?

The complexity of natural mechanisms linking exposure to outcome (D) Signup and view all the answers

What does the term 'confounding' refer to in epidemiological research?

The influence of a third variable on the relationship between the exposure and outcome (B) Signup and view all the answers

What does it mean when a relationship between two variables is 'confounded'?

The relationship is influenced by a third variable (A) Signup and view all the answers

What is the purpose of stratifying data by sex in epidemiological analysis?

To control for the influence of gender on the exposure-outcome relationship (B) Signup and view all the answers

What does it mean to 'adjust for confounding' in epidemiological analysis?

To statistically account for the influence of confounding variables in the analysis (C) Signup and view all the answers

What does it mean when a study result is 'confounded by sex'?

The study result is influenced by differences in the male and female study populations (B) Signup and view all the answers

Why is controlling for confounding variables important in epidemiological research?

To improve accuracy and reduce bias in estimating causal effects (B) Signup and view all the answers

What does it mean to 'adjust for sex' in an epidemiological analysis?

To account for potential gender-related confounding in the analysis (C) Signup and view all the answers

What role does a mediator play in causal inference?

A mediator explains the mechanism through which the exposure influences the outcome (B) Signup and view all the answers

What is the primary purpose of causal mediation analysis?

To assess how much of the total effect operates through a mediator variable (B) Signup and view all the answers

What does it mean when a study result is 'confounded'?

The study result may be biased due to uncontrolled factors affecting the exposure-outcome relationship (C) Signup and view all the answers

What is the definition of a confounder in the context of an association between an exposure E and an outcome D?

A variable C that has an effect on D and is associated with E (A) Signup and view all the answers

What potential problem can arise when including or excluding a confounder C in the analysis?

Both a and b (D) Signup and view all the answers

What is the consequence of not dealing properly with an interaction between variables E and X?

Both c and d (B) Signup and view all the answers

In epidemiology, which are typical confounders when assessing the effect of an exposure of interest?

Sex and age (A) Signup and view all the answers

If there is an interaction between exposure E and third variable X, how should the association between E and D be described?

Describing the association for each level of X (C) Signup and view all the answers

What does it mean when a variable modifies the effect of E on D?

The variable varies among different levels of E (A) Signup and view all the answers

What could be a possible interpretation when comparing two models: one adjusted for a potential confounder and another adjusted for both the potential confounder and a modifying variable?

$\beta$A represents the expected change in the mean outcome for each 1-unit increase in the exposure, when individuals compared have the same levels of potential confounders but different levels of modifiers (A) Signup and view all the answers

In the context of a linear regression model, how is an interaction between variables handled?

By fitting separate models for each level of the interacting variable (A) Signup and view all the answers

$ ext{In a linear regression model, if we suspect that sex (S) modifies the relationship between intima media thickness (IMT) and age (A),}$ $ ext{how should we adjust for this potential modification?}$

$ ext{By fitting separate regression models for each level of sex (S)}$ (B) Signup and view all the answers

$ ext{In epidemiology, when assessing the effect of an exposure on an outcome of interest, what are typical variables that need to be considered as potential confounders?}$

$ ext{Age and sex}$ (C) Signup and view all the answers