Analyses of Binary outcomes

Question 1

Notation: Sample proportion

Answer 1

p=r/n (T or C)

Question 2

Notation: Population odds

Answer 2

pi/1-pi (T or C)

Question 3

Notation: Sample odds

Answer 3

q=r/(n-r) (T or C)

Question 4

Notation: Risk Difference

Answer 4

RD; Pi_T-Pi_C

Question 5

Notation: Risk Ratio

Answer 5

RR= Pi_T/Pi_C

Question 6

Notation: Odds ratio

Answer 6

OR= [Pi_T(1-Pi_C)]/[Pi_C8(1-Pi_T)]

Question 7

The number need to treat formula

Answer 7

NNT= 1/RD

Question 8

assumptions for using Z test

Answer 8

subjects independent

np, and n(1-p) greater than 5 for T and C

Question 9

assumptions for Chi-Squared test

Answer 9

80% of expected frequencies are above or equal to 5

Question 10

advantages of using Risk Difference over Z test?

Answer 10

Can easily calculate Confidence intervals
The EAsily identify the direction of effect
Can calculate easily 1 sided test if appropriate