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 10054 overweight or obese subjects with preexisting
cardiovascular disease and/ or type 2 diabetes. The subjects were
randomly assigned to subitramine ( 5064 subjects) or a placebo (
4990 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 575 subjects in the subitramine group and 503 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 statistic 𝑧= 2.0567 𝑃 ‑value
= .0397 What is the conclusion found from the 𝑃 ‑value? Select the
correct explanation. 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 are unable to come to a
conclusion with the provided information. 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. (b) Why was it important to have a placebo in this
study? Select the correct explanation. None of the reasons are
correct. Because the 𝑃 ‑value is small, there is a no difference in
the proportion of primary outcomes between sibutramine and placebo.
Because the patients might have an extreme reaction to sibutramine
usage. A placebo should be used to blind patients to which group
they are in and to account for any possible placebo
effect.