Critical Thinking: Should you approve this drug?
Drugs must undergo thorough testing before being approved for general use. In addition to testing for adverse reactions, they must also be tested for their effectiveness, and the analysis of such test results typically involves methods of statistics. Consider the development of Xynamine-a new drug designed to lower pulse rates.
In order to obtain more consistent results that do not have a confounding variable of gender, the drug is tested using males only. Given below are pulse rates for a placebo group, a group of men treated with Xy¬namine in 10 mg doses, and a group of men treated with 20 mg doses of Xynamine.
The project manager for the drug conducts research and finds that for adult males, pulse rates are normally distributed with a mean around 70 beats per minute and a standard deviation of approximately 11 beats per minute. His summary report states that the drug is effective, based on this evidence: The placebo group has a mean pulse rate of 68.9, which is close to the value of 70 beats per minute for adult males in general, but the group treated with 10 mg doses of Xynamine has a lower mean pulse rate of 66.2, and the group treated with 20 mg doses of Xynamine has the lowest mean pulse rate of 65.2.
Analyze the Results
Analyze the data using the methods of this chapter.
Based on the results, does it appear that there is sufficient evidence to support the claim that the drug lowers pulse rates?
Are there any serious problems with the design of the experiment?
Given that only males were involved in the experiment, do the results also apply to females?
The project manager compared the post-treatment pulse rates to the mean pulse rate for adult males.
Is there a better way to measure the drug's effectiveness in lowering pulse rates?
How would you characterize the overall validity of the experiment?
Based on the available results, should the drug be approved?
Write a brief report summarizing your findings.
|
Placebo
Group
|
10 mg
Treatment
Group
|
20 mg
Treatment
Group
|
|
77
|
67
|
72
|
|
61
|
48
|
94
|
|
66
|
79
|
57
|
|
63
|
67
|
63
|
|
81
|
57
|
69
|
|
75
|
71
|
59
|
|
66
|
66
|
64
|
|
79
|
85
|
82
|
|
66
|
75
|
34
|
|
75
|
77
|
76
|
|
48
|
57
|
59
|
|
70
|
45
|
53
|