Question

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 9803 overweight or obese subjects with pre-existing cardiovascular disease and/or type 2 diabetes. The subjects were randomly assigned to subitramine (4908 subjects) or a placebo (4895 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 561 subjects in the subitramine group and 492 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? (Note that sibutramine has not been available in the United States since the end of 2010 due to its manufacturer's concerns over increased risk of heart attack or stroke, although at the present time it can still be purchased in other countries.)

State hypotheses, find the test statistic, and the P-value. (Round your test statistic to two decimal places and your P-value to four decimal places.)

H0: Ptreatment (? = ≠ < >) Pplacebo (CHOOSE ONE OF THE SYMBOLS IN THE PARENTHESES)

Ha: Ptreatment (? = ≠ < >) Pplacebo  (CHOOSE ONE OF THE SYMBOLS IN THE PARENTHESES)

P-value = _____z = ______

State your conclusion. (Use α = 0.05.)

A.) Because the P-value is large, we have evidence that there is a difference in the proportion of "primary outcomes" between subitramine and placebo.

B.) Because the P-value is small, we have evidence that there is a difference in the proportion of "primary outcomes" between subitramine and placebo.

C.) Because the P-value is small, we do not have evidence that there is a difference in the proportion of "primary outcomes" between subitramine and placebo.

D.) Because the P-value is large, we do not have evidence that there is a difference in the proportion of "primary outcomes" between subitramine and placebo.

Answer 1

Because the P-value is small, we have evidence that there is a difference in the proportion of "primary outcomes" between subitramine and placebo.