Association, Causal Inference & Causality Flashcards
Define cause.
A precursor event, condition, or characteristic required for the occurrence of the disease or outcome
What are the three types of associations?
- Artifactual (aka False)
- Non-causal
- Causal
What association can arise from bias and/or confounding?
Artifactual
What two ways can non-causal associations occur?
- Disease may cause the exposure
2. The disease and the exposure are both associated with a third factor (confounding)
What is a causal association?
Exposure ——> Outcome
What are the types of causal relationships?
- Sufficient cause
- Necessary cause
- Component cause
Define Sufficient Cause.
A set of minimal conditions/events that inevitably produce disease
Cause precedes the disease and will always cause disease; rare, apart from genetic abnormalities
Define Necessary Cause.
A cause which precedes a disease; must be present for the disease to occur however the cause may also be present without the disease occurring
Define Component Cause.
A factor/element that, if present/active, increases the probability (or likelihood) of a particular disease
Some pts must be “primed” or “susceptible” to disease before Component Causes induce disease
What is Component Cause also known as?
Risk Factor, RF
What are the interactions of causal relationships?
- Synergism
2. Parallelism
Define Synergism
- Factors work together
- Biological-interaction of 2+ component-causes such that the combined measure of effect is greater than the sum of the individual effects
Define Parallelism
- Factors that work in parallel
- Biological-interaction of 2+ component-causes such that the measure of effect is greater if either is present
What is Multiple Causation?
Multiple Component-causes working in concert to collectively become Sufficient-causes
What is the Epi Causal Inference Process?
Hill’s Guidelines
What are Hill’s Criteria?
- Strength
- Consistency
- Temporality
- Biologic Gradient
- Plausibility
Define Strength
Refers to the size of the measure of association (RR/OR/HR)
The greater the association the more convincing it is that the association might actually be causal
Define Consistency
The repeated observations of an association in different populations under different circumstances in different studies
What is Consistency also known as?
Reproducibility
Define Temporality
It reflects that the cause precede the effect/outcome in time
Time-order also describable: proximate cause (short-term) and distant cause (long-term)
Define Biologic Gradient
Presence of a gradient of risk (dose-response) associated with the degree of exposure
Define Plausibility
Presence of a biologic feasibility to the association, which can be understood and explained (biologically/physiologically/medically)
