Measuring Risk Flashcards
What are the three sides of the pathogenic triangle?
- Host
- Agents
- Environments
What is latency?
Time between exposure and event
What are the RF for Coronary Artery Disease (CAD)?
- Age
- Male sex
- DM
- Smoking
- HTN
- Cholesterol (total)
- LV hypertrophy
What did John Snow do?
Mapped out Cholera cases in London. Asked them to remove a pump.
What is absolute risk?
Probability of an event in a population under study.
=incidence
What is attributable risk?
Incidence of disease in an exposed person, minus the incidence of diz in non-exposed.
It is the additional incidence of diz related to exposure.
Aka risk difference
What is relative risk?
How many times more likely are exposed persons get the disease compared to non-exposed.
How can you interpret RR>1?RR
RR>1 = risk of a bad outcome is increased by your tx (independent variable)
RR
What is relative risk reduction?
How much the tx reduced the risk of bad oucome, relative to a control w/o the tx.
What is another way to express ARR?
Number needed to treat (NNT)
=100/ARR
Using the table, give formulas for CER. EER. RR. RRR. ARR. NNT
Yes. No Exposed. A. B Not exposed. C. D
Control event rate (CER) = c/c+d
Experimental event rate (EER) = a/a+b
Relative Risk (RR) = EER/CER
Relative Risk Reduction (RRR) = CER-EER/CER ; ARR/CER
Absolute risk Reduction (ARR) = CER-EER
Number needed to tx (NNT) = 1/ARR
Number needed to harm (NNH) = 1/(ARR of developing harmful side effect)
Which is better for measuring the effect size; RR or ARR?
Probably ARR
What is Relative risk reduction?
1-RR
Just another way to phrase relative risk.
