Discussion

• 1. Why were participants divided into groups by lot? What are placebos and why were they used?
  
  
• 2. Why were participants required to meet the criteria given?
  Why were they allowed to continue present medications?
  Would the study have been better if they were not?
  
  
• 3. The article reports that there were 543 patients in the ritonavir and 537 in the placebo group. Using the percentages given in the article, find the number of patients in each group who died or suffered further progression of AIDS. How many patients in each group died?
  
  
• 4. If retonavir makes no difference, how many of the 72 patients who died would you expect in each group? If you toss a coin 72 times do you think there is a reasonable chance that you would get as many as 46 heads? What could you do to help you answer this question? What does this have to do with the study?
  

Homework assignments for Monday February 12.