Question

In placebo controlled clinical trials for the drug Viagra, 734 subjects received Viagra and 725 subjects received a placebo (subjects did not know which treatment they received). The table below summarizes the various side effects reported

Adverse Effect Viagra (n=734) Placebo (n = 725) Headache 117 29 Flushing 73 7 Dyspepsia 51 15 Nasal Congestion 29 15 Urinary tract infection 22 15 Abnormal vision 22 Diarrhea 22 7 Dizziness 15 7 Rash in 7

PLEASE Endeavor to answer all questions and please make your answes as visible and coherent. thank you.

Question One
What is the variable in this experiment and Is the variable qualitative or quantitative?

QUESTIONS TWO

Make a graph of the data and upload it to this question. You may use technology or draw the graph by hand. Be sure to include all necessary labels.

QUESTION THREE
What is the probability that a randomly selected subject from the Viagra group reported flushing as an adverse effect? Give your answer as a decimal rounded to three places along with the probability statement.

QUESTION 4.
Would it be unusual for a randomly selected subject from the Viagra group to report flushing? Briefly explain.

QUESTION 5
What is the probability that a randomly selected subject from the Placebo group reported flushing as an adverse effect? Give your answer as a decimal rounded to three places along with the probability statement.

QUESTION 6

Would it be unusual for a randomly selected subject from the Placebo group to report flushing? Briefly explain.

QUESTION 7

a)If a subject reported flushing after receiving a treatment, what might you conclude?
B)What type of experimental design is this?

Answer 1

QUESTION ONE:
The variable in this experiment is the Type of Drug received with 2 distinct categories:

(a) Viagra (b) Placebo

We find that the data collected is in the form of Counts, where, we are interested in the figure - No. of subjects in the each category, who shows the symptom of interest. Hence, we may say that the data is categorical or qualitative - the outcome is recorded in the form of categories).

QUESTIONS TWO

Graphing the given data - We may use the bar chart to compare the counts of subjects who receive viagra and placebo for each of the side effects.

140 117 120 100 80 73 Frequency Viagra 60 51 Placebo 29 29 40 20 22 22 22 15 15 15 5 15 7 7 7 7 0 0 Headache Flushing Dyspepsia Diarrhea Dizziness Rash Nasal Congestion Urinary Tract infection Abnormal vision

From the graph, we get a rough idea that the side effects observed are greater in those subjects who received the drug Viagra as compared to those who received placebo.

QUESTION THREE

By definition of probability,

Probability of occurrence of an event = No. of favorable events / Total No. of events

Hence, the probability that a randomly selected subject from the Viagra group reported flushing as an adverse effect

Pr(Flushing) = 73 / 734

= 0.099

The probability that a randomly selected subject from the Viagra group reported flushing as an adverse effect is 0.099.

QUESTION 4.
Since, the probability that the selected subject from the Viagra group would report flushing is about 10% (> 5%), we may say that out of every 10 persons who received Viagra, 1 would report the symption of flushing. Hence, we may say that it would not be unusual for a randomly selected subject from the Viagra group to report flushing.

QUESTION 5
The probability that a randomly selected subject from the Placebo group reported flushing as an adverse effect

Pr(Flushing) = 7 / 725

= 0.010

The probability that a randomly selected subject from the Placebo group reported flushing as an adverse effect is 0.010.

QUESTION 6

Since, the probability that the selected subject from the Viagra group would report flushing is about 1% (< 5%), we may say that out of every 100 people who received Viagra, 1 would report the symption of flushing. Hence, we may say that it would be unusual for a randomly selected subject from the Placebo group to report flushing.

QUESTION 7

a) If a subject reported flushing after receiving a treatment, we may say that there is a strong evidence to support the claim that flushing is a side effect of the drug Viagra.

b) Here, we find that the experiment is a placebo controlled study where, we study distinct groups   1. Treatment group - Subjects who receives the study drug 2. Control group - Subjects who receive the Placebo

Also, we observe that the subjects were blinded as to which drug the received - Viagra or Placebo.

Hence, we may say that the given experiment is a Blinded Placebo controlled experiment.