Subjects with pre-existing cardiovascular symptoms who were receiving subitramine, an appetite suppressant, were found to be at increased risk of cardiovascular events while taking the drug. The study...

Extracted text: Subjects with pre-existing cardiovascular symptoms who were receiving subitramine, an appetite suppressant, were found to be at increased risk of cardiovascular events while taking the drug. The study included 9719 overweight or obese subjects with preexisting cardiovascular disease and/ or type 2 diabetes. The subjects were randomly assigned to subitramine (4787 subjects) or a placebo (4932 subjects) in a double-blind fashion. The primary outcome measured was the occurrence of any of the following events: nonfatal myocardial infarction or stroke, resuscitation after cardiac arrest, or cardiovascular death. The primary outcome was observed in 557 subjects in the subitramine group and 505 subjects in the placebo group. Do the data give good reason to think that there is a difference between the proportions of treatment and placebo subjects who experienced the primary outcome? (a) State hypotheses, find the test statistic and use either software or Table A for the P-value. Give both the test statistic and the P-value to three decimal places. Test statisticz = P-value = What is the conclusion found from the P-value? Select the correct explanation. O We have strong evidence that the proportion of subjects on sibutramine who are suffering a primary outcome differs from those who are on the placebo. We have no evidence that the proportion of subjects on sibutramine who are suffering a primary outcome differs from those who are on the placebo. We have very little evidence that the proportion of subjects on sibutramine who are suffering a primary outcome differs from those who are on the placebo. O We are unable to come to a conclusion with the provided information. (b) Why was it important to have a placebo in this study? Select the correct explanation. A placebo should be used to blind patients to which group they are in and to account for any possible placebo effect. O Because the patients might have an extreme reaction to sibutramine usage. O None of the reasons are correct. O Because the P-value is small, there is a no difference in the proportion of primary outcomes between sibutramine and placebo. O O O O