302 Representing risk Flashcards
1
Q
How do you calculate incidence?
A
Number of people who develop disease of a given time
/
number of people at risk of developing disease over a given time
2
Q
What is the relative ratio (RR)?
A
The risk of developing a disease in exposed group compared to developing a disease in unexposed group
3
Q
How is RR calculated?
A
Incidence of disease among exposed
/
incidence of disease among non-exposed
4
Q
What is meant by strength of association with RR?
A
RR of 1.5: risk of outcome 50% higher in exposed than unexposed group
RR of 3.0: risk in exposed group is three times as high as unexposed
RR of 0.8: risk of outcome 20% lower in exposed than unexposed group
5
Q
What is the P value?
A
Probability
6
Q
What are confidence intervals?
A
A way of expressing the precision of estimates
