Name __________________
1) For a casecontrol study of resistant TB and HLA type AB, the cases and controls were matched on ethnicity. The results are in the following table:

Control HLA AB 
Control not AB 
Case HLA not AB 
25 
39 
Case HLA AB 
47 
75 
a) Compute the odds ratio; what does it mean?
b) Test the odds ratio; what is the null hypothesis you are testing?
c) Estimate the odds ratio’s confidence interval.
2) A casecontrol study of regular exposure to second hand smoke (y/n) and endometrial cancer needs to be adjusted for the age of the women involved. The tables split by age group are below:
Age 1835 
E. Cancer  
E. Cancer + 
Exposure  
15 
50 
Exposure + 
30 
25 
Age 3655 
E. Cancer  
E. Cancer + 
Exposure  
30 
25 
Exposure + 
15 
50 
a) What would be the odds ratio for each age group?
b) What do they mean in words?
c) Compute the adjusted odds ratio?
d) How would you report results and what are your conclusions?
3) Suppose you have the following twobyfour table of a disease versus age groups based on a casecontrol study:

1825 
2635 
3645 
45+ 
Disease  
777 
301 
1243 
123 
Disease + 
189 
91 
355 
60 
Answer whether disease rates are different across groups? Which rates are different?
Perform proper test(s), estimation and interpret the results.
4) Suppose the results of a simple logistic regression are represented in the following STATA output:
Write the model equation which associated with this logistic regression, explain all terms in the model. Explain meaning of all the numbers in the output. Calculate OR if age is increased by 12 years (measurement unit is 1 year for the age variable) and find 95% confidence interval for that.
5) Explain the output and find OR to develop CHD between groups 1 and 4.