PPT 3 Flashcards
What is a causal pie model
each pie is composed of a component cause
can there be multiple pies to explain how disease happens
yes
what is multicausality
every causal mechanism involves the joint action of multiple component causes
give an example of causes
genetics and environmental
true or false very few exposures cause disease entirely by themselves
false
What is another name for sufficient cause
causal mechanism
Is sufficient cause the whole pie
yes
what is the definition of sufficient cause
a minimum set of conditions when one is missing disease wont occur
is sufficient cause usually a single factor
no each factor is a component cause
What is a component causes
an event or condition that plays a necessary role in the occurence of some disease
List four component causes of pneumonia
- elderly person
- exposure to pneumococcus
- smoking
- lives in a nursing home
Name 3 pies for CAD
1- age, high cholesterol, smoking, obesity
2- genetics, sex, menopause, hormone replacement therapy
3- hypertension, unknown factor, maternal under nutrition, diabetes
What is a necessary cause
the most important piece of the pie without it disease wont occur
What is a necessary cause example
Example would be finding a component cause it each causal pie
what is strength of causes
some component causes play a more important role than others
Do causal components act in concert to produce effect
yes
What is a strong cause
its a component cause that plays a causal role in a large proportion of the cases
what is a weak cause
is a causal component in a small proportion of cases
Strength of the cause depends on what
the prevalence of other causal factor that produce disease
What is completion of a sufficient cause
disease occurrence (maybe not diagnosed)
What does blocking of a component do to the completion of a sufficient cause
prevents the completion ex: no disease
What is induction period
period of time beginning at the action of a component cause and ending when the final component cause acts and the disease occurs
What is latency period
refers to time delay between disease occurrence and its detection
Can component cause act far apart in time
yes
How do we know when something “causes” something else?
Look at mill’s canons
What are the 5 things of Cannon
Temporal Sequence
Strength of association
Consistency
Dose response
Biological Plausibility
Temporal sequence
Exposure of the risk factor must precede development of the disease with sufficient time to account for disease progression
Strength of association
There is a large and clinically meaningful difference in disease risk between those exposed and those not exposed to the risk
Consistency
The observed association is always observed if the risk factor is present (e.g., regardless of sex, race, age, or methods of measurement)
Dose response
The risk of disease associated with the risk factor is greater with stronger exposure to the risk factor
>exposure to risk factor, > risk of disease
Biological Plausibility
The observed association is explainable by existing knowledge about possible biological mechanisms of the disease, which may be alterable (e.g., by physical activity)
