Does the use of stents reduce the risk of stroke? Stents are small mesh tubes th
ID: 3126319 • Letter: D
Question
Does the use of stents reduce the risk of stroke? Stents are small mesh tubes that are placed inside narrow or weak arteries to assist in patient recovery after cardiac events and reduce the risk of an additional heart attack or death. Researchers randomly assigned 224 of the volunteer patients who were deemed to be “at risk” to the treatment group which received stents along with medical management (medications, dietary support, etc). The remaining 227 volunteers were assigned to the control group which received the same medical management but did not have stents surgically implanted. The data from 1 year after the study began is displayed in the table below.
Stroke
No event
Total
Treatment
45
179
224
Control
28
199
227
Total
73
378
451
Is this an experiment or an observational study?
Define a “success” as having a stroke. What is the proportion of successes for the treatment group?
What is the proportion of successes for the control group?
Without conducting a hypothesis test, does it appear that stents reduce the risk of stroke? Explain your reasoning.
Stroke
No event
Total
Treatment
45
179
224
Control
28
199
227
Total
73
378
451
Explanation / Answer
It is an experimental study.
Out of 224 patients in treatment group, 45 has storke so the proportion of successes for the treatment group is
45 / 224 = 0.2009
-------------
Out of 227 patients in control group, 28 has storke so the proportion of successes for the control group is
28 / 227 = 0.1233
------------------
No becuase the proportion of stroke in treatment group is greater than control group.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.